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Do migrants relieve or intensify the plight
of the developing world? The cities are filling up and urban unemployment steadily grows ..... the 'marginal men', the wretched strugglers for survival on the fringes of form and city, may already number more than half a billion, by 1990 it was two billion. Can we imagine any human order surviving with so gross a mass of misery piling up at its base? (Robert McNamara, former President of the World Bank). Rural-urban migration was viewed favourably in economic development literature. Internal migration was thought to be a natural process in which surplus labour was gradually withdrawn from the rural sector to provide needed manpower for urban industrial growth. The process was deemed socially beneficial since human resources were being shifted from locations where these social marginal products were not only positive but also rapidly growing as a result of capital accumulation and technological progress. As Richard Jolly, former Director of the Institute of Development Studies of the University of Sussex, has noted, 'Far from being concerned with measures to stem the flow, the major importance of economists who stress the importance of labour transfer was with policies that would release labour to increase the flow. Indeed, one of the reasons given for trying to increase productivity in the agricultural sector, was to release sufficient labour for urban industrialisation. In contrast to this viewpoint it is now abundantly clear from recent experience that rates of rural-urban migration continue to exceed rates of urban job creation and to surpass greatly the absorbtion capacity of both industry and urban social services. No longer is migration viewed by economists as a beneficent process necessary to solve problems of growing urban labour demand. On the contrary, migration today must be seen as the major factor contributing to the ubiquitous phenomenon of urban unemployment problems caused by economic and structural imbalances between urban and rural areas. Migration exacerbates these rural-urban structural imbalances in two direct ways. First on the supply side, internal migration disproportionately increases the growth rate of urban job seekers relative to urban population growth, because of the high proportion of well educated young people in the migrant system. Their presence tends to swell the growth of urban labour supply while depleting the rural countryside of valuable human capital. Second, on the demand side, urban job creation is generally more difficult and costly to accomplish than rural employment creation because of the need for substantial complementary resource inputs for most jobs in the industrial sector. Together this rapid supply increase and lagging demand growth tend to convert a short-run problem of manpower imbalances into a long-run situation of chronic and rising urban surplus labour. We must recognise at the outset, therefore, that migration in excess of job opportunities is both a symptom of and contributor to developing world underdevelopment and intensifies the unemployment plight of the developing world. The factors influencing the decision to migrate are varied and complex. Emphasis has variously been placed for example on - social factors; including the desire of migrants to break away from traditional constraints of social organisations. Physical factors, including climate and meteorological disasters like floods and droughts. Demographic factors include the reduction in mortality and the high rates of rural population growth, cultural factors include the security of urban 'extended family' relationships and the allurement of the 'bright city lights'. Communication factors including improved transportation, urban oriented educational systems, and the 'modernizing' impact of the introduction of radio, television and the cinema. It is convenient to divide the main characteristics of migrants into three broad categories: demographic, educational and economic. Demographic characteristics Educational characteristics Economic characteristics The economic development of Western Europe and the United States was closely associated with the movement of labour from rural to urban areas. For the most part, with rural industrialisation, overall economic development in these countries was characterised by the gradual relocation of labour out of agriculture and into industry through rural-urban migration. But the overwhelming evidence of the 1960s and 1970s, when the developing world nation's witnessed a massive migration from their rural populations into urban areas, despite rising levels of urban unemployment. This created major problems for the urban areas, shanty towns were set-up, people could not fulfil their expectations of getting a paid job in the cities. This led to increase in unemployment and poor sanitation conditions and rapid poverty surrounding developing world cities. Migration is stimulated primarily by rational economic considerations of relative benefits and costs, mostly financial but also psychological. Migratian takes place in the third world because urban wage rates grow at a greater pace than average rural incomes and thus this will stimulate further rural-urban migration inspite of rising levels of urban unemployment. The traditional Keynesian economic solution to urban unemployment i.e. the creation of more urban-sector jobs without attempts to improve rural incomes and employment opportunities can result in the paradoxical situation where more urban leads to higher levels of urban unemployment! Higher urban employment rates will widen the expected differential and induce even higher rates of rural-urban migration. For every new job created, two or three migrants who were productively occupied in rural areas may come to the city. Thus if 100 new jobs are created there may be as many as 300 new migrants and therefore too many urban unemployed. A policy designed to reduce urban unemployment, therefore may lead not only to higher levels of urban unemployment but also to lower levels of agricultural output. Unemployment in the countryside is relatively low in the developing world. The lack of rural employment is usually reflected to a greater or lesser degree by a state of under-employment, rather than actual over unemployment in the modern sense of the term. The great speed with which the process of urbanization has proceeded in the developing world has led to deterioration of the possibilities for employment in most urban centres. The number of additional workers who came into the labour market as a consequence of migrations to towns between 1950 and 1970 can be estimated at some 60 to 70 million. The doubling of the urban working population occurring between 1950 and 1970 has created an employment situation so unfavourable that it was bound to be reflected by the under-employment in the tertiary and other sectors of the labour force, and by an unemployment rate which climbed in most countries to an unacceptably high level. Another serious feature is that the urban unemployed person in the developing world is nearly always one who has had an average education i.e. a young person who has completed six to eleven years of schooling. The highest unemployment rates are to be found in this category. Programs of integrated rural development should be encouraged. Policies of rural development are crucial to this aim. Many informed observers of developing world development agree on the central importance of rural and agricultural development if the urban unemployment problem is to be solved. Most proposals call for the restoration of a proper balance between rural and urban incomes and for changes in government policies that essentially give development programs a strong bias toward the urban industrial sector. Given the political difficulties of reducing urban wage rates the need continuously to expand urban employment opportunities through judicious investments in small and medium scale labour intensive industries and the inevitable growth of the urban industrial sector, every effort must be made to broaden the economic base of the rural economy at the same time. To conclude, clearly any long-term solution to Developing World employment and urbanization problems must involve a lowering of current high rates of population growth. Even though the labour force size for the next two decades is already determined by today's birthrates, 'the hidden momentum' of population growth applies equally as well to labour force growth. Together with demand policies, the population and labour supply reduction policies provide an essential ingredient in any strategy to combat the very serious and worsening employment problems that developing countries face now and in future years. One of the principle factors inhibiting the success of any long-run program of employment creation both in urban industry and rural agriculture is almost complete technological dependence of developing nations on imported typically labour saving machinery and equipment from the developed world. Both domestic and international efforts must be made to reduce this dependence by developing technological research and adoption capacities in the developing countries themselves. Such efforts to reduce unemployment might first be linked to the development of small-scale labour intensive rural and urban enterprises. They could also focus on development of low-cost labour intensive methods of providing rural infrastructure needs including roads, irrigation and drainage systems and essential health and educational services. Clearly this is an area whose scientific and technological assistance from the developed countries could prove extremely fruitful. Finally migration does increase unemployment in the developing world, because many uneducated workers leave the agricultural rural areas to seek their fortune in the urban areas, but in many instances dreams and expectations do not materialize, because the ratio of migration floods the positions for jobs. Migration only relieves unemployment in the rural areas but it is not an economical policy that should be pursued. Tamil Separatism and the examples of Britain,
Cyprus and Bangladesh Continued from yesterday The Irish parliament had no control over the English officers who were sent to rule Ireland. Further the economy of Ireland suffered. It was stifled in order to develop that of England. Ireland's cattle and wool were at one time the best in Europe, but both declined after the English conquest. In 1720 the British transferred to the English House of Lord, the powers of the supreme court in Irish case law. There was deep resentment. By the end of the 18 century, there was an attempt to lessen the persecution of the Catholics. The laws which prevented them from buying land was repealed in 1778 and fresh reforms were planned but the Protestants objected fearing for their position. There was rebellion in 1798. And as a result, in 1801 there came an amalgamation of the English and Irish Parliaments, merging the kingdoms of Ireland and Britain into the 'United Kingdom'. Irish peers and representatives were admitted to the English Parliament. Ireland was to keep her own judicial system, subject to British approval. There was to be free trade between the two regions, and Ireland was to contribute a percentage of her revenue to the revenue of the United Kingdom. Most important this Act of Union had also offered the understanding that Catholic emancipation be granted. This was not done however and the Irish were represented in Parliament by Protestants of the landowning class. There was much agitation led by the Irish leader Daniel O'Connell and in 1829 came the Roman Catholic Emancipation Act which gave Catholics complete civil, political, legal and economic freedom. They were able to hold office and the professions were open to them. Irish Church Act of 1869 said that the Protestant Church was no longer the official church and the Church gave up some of its lard and its wealth. This angered the Protestants. The 19 century was characterised by two developments. Firstly, due to harsh economic conditions, many emigrated. There was a terrible famine in 1845, when the potato crops caught a disease. Many starved. There began a steady flow of emigration to Britain, Australia, New Zealand, Canada and above all USA, encouraged by the Irish who were already there. In the meantime a formidable political organisation began called the 'Fenian Society' which wished to draw attention to Ireand's plight by force and violence, including the use of bombs. This was in a sense the beginning of terrorism in Ireland. There were some positive results of this agitation. The Protestant Church and the Catholic church was put on par, and Land Acts in favour of the peasantry were passed. But this did not satisfy the population. The Irish emigrants to Canada, Britain and USA carried their bitterness towards Britain with them. And in these countries they, the exiles helped support and develop the resistance to Britain. In 1858 the Irish immigrants in America founded the 'Irish Republican Brotherhood' with its own newspaper, societies and fund raisers. They advocated aggressive tactics in Britain and elsewhere. They also founded the 'Land League' of 1879 which was eventually led by Parnell. In the meantime, Britain had granted the right of 'Home Rule' to its other colonies, America, Australia and Canada, but refused this to Ireland. Ireland kicked and rebelled, until in 1920, the Government of Ireland Act appeared. This Act partitioned Ireland into North and South with separate parliaments in Dublin and Belfast. By this time, through a series of Land Acts, the greater part of the land was owned by the Irish, which by now included the early settlers. The Catholic south was named the 'Irish Free State'. However the north, including the solidly protestant Ulster were not made a part of the Irish Free State, but stayed as a part of Britain, as 'Northern Ireland.' The call for 'Home Rule' was a call for a free and united Ireland. Not for partition. The leader in this was the Irishman Charles Parnell. This call was strenuously opposed by the Irish Protestants. So we can see how, the political conflict started. As usual there was rebellion, and violent repression. The Irish Republican Brotherhood got ready for revolution. The Sinn Fein ('We ourselves') came up led by Eamon de Valera. They tried to set up an independent government. The Irish Republican Army (IRA) came into being, to resist the Brisith administration and to secure recognition for the Republican government. Its members soon engaged in widespread ambushes and attacks on barracks, and the British government retaliated. (In 1916 Sinn Fein demanded complete independence. Then came a two year period which was really 'civil war' where the Sinn Fein and the British army fought ruthlessly. The British army and also the Royal Irish Constabulary were both armed, and they were very cruel in their operations against the Sinn Fein. The world was shocked. The 1920 Act was the result. It was obtained from Britain through violence. The Irish leaders toured the USA in 1920 and obtained the funds to finance their operation. De Valera was not satisfied with the 'Dominion status' granted to the Irish Free State. In 1937 he brought in a new constitution, which declared a republican goveernment which was sovereign, independent and democratic. It was to be called 'Eire" and its official language was to be Irish. Britain recognised the Republic of Eire in 1949. It is today an independent state with a seat in the United Nations. Thereafter attention turned on the region of Northern Ireland. Northern Ireland is economically and politically a part of the United Kingdom. Until 1972 the King exercised all legislative powers in Northern Ireland through a governor. And London retained power over foreign affairs, trade and other subjects of national importance. There was however a separate Parliament in Northern Ireland, called the Stormont. The main trade link was with Britain trade with Eire was negligible. In 1972, after years of political violence and terrorism, Britain suspended the Northern Ireland Parliament and placed Northern Ireland under direct rule. A Secretary of State for Northern Ireland was appointed. The political scene was dominated by the single issue of union with Britain or union with Ireland. The Catholics in Northern Ireland wanted union with the newly independently Republic of Eire. The Protestants in Northern Ireland wanted the region to remain as a part of the United Kingdom. The Protestants were invariably in the majority in parliament and Catholics were usually in the opposition. The Protestants wanted a 'Protestant state for a Protestant people'. About 25% of the population were Catholics the rest were Protestants. The elites, both landowning and commercial, were Protestant, and they gained the allegiance of the lower class Protestants by playing on their fears of Catholic domination. There developed the Orange Order, which commemorated an event in 1960, but was actually intended to demonstrate the victory of the Protestants over the Catholics. This Order persisted and spread to England and the Irish Protestant communities abroad. However the distribution is very uneven and towns far from Belfast have Catholic majorities. In towns there is a high degree of segregation. The Protestants and Catholics do not mix. Belfast is split in the west into two sections. The Falls Road is exclusively Roman Catholic and Shankhill Road is Protestant. In many streets segregation is 100 percent, and this applied mainly to low income areas. Civil disturbance was always concentrated in areas where segregation was highest. The Catholics were discriminated against. Delimitation was done to ensure that few Catholics got into parliament. Catholics were denied jobs. Protestants got priority in housing, education, jobs contracts. Employers refused to employ Catholics. The Protestants always fiercely resisted independence from Britain. They opposed all Home Rule Bills, from 1886. When in 1912, Home Rule seemed imminent, Protestant Ulster, under Edward Carson prepared to resist incorporation into a self-governing Ireland. Paramilitary forces were organised and armed. Civil war between north and south seemed imminent. Therefore it should not come as a surprise to find that from 1950 onwards, after the Republic of Eire and separated from Northern Ireland there was continuous fighting in Northern Ireland between the Protestants and Catholics. In 1965, Britain passed its Race Relations Act of 1965, to safeguard the rights of its coloured citizens. In 1968, the Catholics formed the Civil Rights Movement of Ulster. These civil rights protests rekindled religious and political conflicts in Northern Ireland, particularly in Belfast and Derry. The Irish Republican Army (IRA) came back to life in the form of urban guerrillas who undertook to protect the Catholic areas from assault. The Protestants formed their own paramilitary brigade,. such as the Ulster Volunteer Force (UVF). The guerilla warfare threatened to wreck Ulster. Town centres were destroyed, army barracks attacked. Continued tomorrow Assessment for selection must be assessment
to support learning (Continued from yesterday) This is a continuation of the article 'Implcations of the Common General Paper of the GCE (A/L) exam for selection to Universities Differences is mean test achievement from school to school are uusually far longer than would result from simple random sampling, and are almost as great as differences among individual pupils within a single school. The same item may prove very difficult in one school and very easy another, or very discriminating in one school and non discriminating in another. For these reasons the number of schools represented in the tryout is important, as well as the number of students.' A tryout sample of 20,000 pupils all taken from the school system will generally not serve as well as a sample of 400 pupils taken from many school systems' says Linguist, the great psychometrician. In this test the order of difficulty appears to be erratic. Some of the early items are quite difficult, and some of the later items, are extremely easy. It is difficult to believe that successive drafting of the test were tried out experimentally in the way advocates by psychometricians. The statement that 78 percent passed in the paper suggests that this has been no tryout attempt at all. It is similar to a traditional teacher made test. The optimum difficulty of the test items defends critically on the purpose, which is selection of 10 per cent of the students. The items should cluster round a particular difficulty cut-off point. As it is to select the best 10 per cent, most of the items should be difficult ones, so that they are answered correctly by about half the population at the 90th percentile of difficulty. If the items are mainly easy ones, the test will discriminate the less able student with useless efficiency, but will fail to pick the 10 per cent accurately. Just imagine the damage caused to students by this test. Item analysis method should be used with discrimination and understanding. Guilford has pointed out that the procedure of omitting the middle section of the sample using the Higher Group of performance with the lower group of performance, the values would remain comparable for different items, which in what it matters. It provides a single, simple index for comparing the value at different items. These principles have been grossly ignored constructing the C. G. P. Eyesenck states that 'no success can be expected from the haphazard throwing together of items and test of unknown difficulty or factorial composition, a practice unfortunately to widespread. Only the must rigorous testing of the tests themselves, by the use of item analysis and the various other techniques elaborated for this purpose, can ensure that technical competence in test construction so absolutely essential for fruitful works, and so deplorably missing in many published tests'. How apt this statement for the C.G.P. in Sri Lanka. Mr. W. J. M. Lokubandara as Minister of Education and Higher Education mooted the idea of introducing three subjects at G.C.E. (A/L). The change was very widely welcomed by the University dons who interacted on this subject on three occasions. He did not envisage the replacement of subjects like Botany and Zoology by Biology or Pure Mathematics and Applied Mathematics by Mathematics. He expected those subjects to remain at the G.C.E. (A/L) examination as in the case with G.C.E. (A/L) London where more than 100 subjects are included. He suggested the achievements of students to be raised through a well - timed well-targeted and well-delivered programme to develop the intellectual ability of students. Meanwhile, the Universities imposed subject combinations for various streams thereby generating unexpected problems for schools and students. It also infers the acceptance of aptitudes of a student. It was a rigid form of selection. Taking into consideration changes in society and the world of work it was realised that a student should be able to apply knowledge and skills in many contexts. A crucial issue was the basis on which the components of the curriculum should be formed in order to provide for a balanced and relevant curriculum for all students. There was to be a core of the subject or areas of study judged essential for the learning of all young students. A number of practical examples, the Scottish model. The International Baccalaureat, the proposed British Baccalaureat and proposals put forward by the Royal Society were carefully examined. In doing so stress was made on the importance of knowledge and applied intelligence. This subject, on balance, the best practical approval in to include a small number of basic areas as (1) English 10 marks (2) Mother Tongues (30 marks) (3) Natural Science and Technology (20 marks) (4) Expressive arts and culture (20 marks) (5) Humanities (Geography and History) 20 marks. A low rank order of 10 marks is given to English, so that it would not adversely affect the rural child. It was essential to heed the needs of employers who emphasised on effective communication in English which involves the use of ability to read, write, and listen. An English Teaching payment was launched with the assistance of the World Bank and the Peradeniya University. Teachers of English were recruited from among the retired personnel who were trained for the task. It was targeted to produce 1000 graduates with English as a second subject by the year 2000. Current cognitive theory, suggests that assessing separate components will encourage the teaching and practise of isolated components and this is not sufficient for learning problem solving or thinking skills. Efforts to access thinking and problem solving abilities and testing them independently is not conducive to learning. The C.G.P will not contribute to better learning in the University. Assessment for selection must be assessment to support learning. In that respect thinking skills can be achieved through the curriculum. Thus the fourth subject can be as suggested by the then Minister of Education. My humble attempt here is to pin down the various misconceptions and implications of these policies to educational and economic development of Sri Lanka and to the students in general. A superficial consideration of the situation can easily lead to the assumption that the paper is necessarily good. The aim of education today appears likely to be served best by a continuing and discriminating search for the most equitable, accurate and acceptable test necessary to identify the few destined for further educational advancement and at the same time reinforce the self-esteem of the many for whom the G.C.E. (A/L) is terminal, by providing useful information about their achievement and capabilities. It should be borne in mind, that an enlightened form of examination can be a conscious instrument for educational development. Science Tomorrow the Annual Sessions of the Institution of Engineers of Sri Lanka commence. Engineers fall at the bottom of the heap in the eyes of our society. But engineers are those who contribute most to the development of this country. We fall behind the politicians, doctors , architects etc in order of importance as conceived by the average citizen, when necessary to satisfy his or her needs. If one does agree with this statement, or not it is time that the Institution carried out a survey on the value placed by Society on the various professions in Sri Lanka. Such surveys are carried out by professional bodies in many countries. In most of these surveys the politician falls to the bottom . But in Sri Lanka the politicians have come to the top because the professionals have over the past 50 years withdrawn from the decision making roll at the execution stage of the policy. We acknowledge that politicians are the law makers on behalf of the people, which generate the policy for the public servants to work. But not beyond, for good government. A classic example of this political decision making , was reported in the Media. The Railway Station in Galle which was in the books for many years , to be shifted to make the, train continue to Matara without, reversing in Galle, had been abandoned after the ministers visit. Such examples are numerous. The community need not come to the Engineer to get his needs satisfied . The average man knows that it is the politician who fixes his problem, and not the Engineer, The Engineer is a glorified Tradesman in the eyes of the citizen. How can we correct it. It is this type of experience seen in the past 2 years , after living in Australia for 25 years that made me Nominate for the post of Hon Secretary of your Institution. I would be accepting this appointment without contest in the new year, in all humbleness, to try and change the views of our society towards the Engineer, when We approach the new millennium. Like many an engineer in the 60's who expressed their views to politicians ,without reservation, I too expressed my view on political interference in the State Engineering Cooperation to Comrade Pieter Keuneman. The process of politicising the SEC had just began in 1970. I as President of the Engineers union . had to point out the unnecessary influx of Russian Engineers etc to SEC, as well as union bashing by thugs of the Communist party. These events resulted in my Interdiction from SEC. Even though I was invited by Mr Keuneman after one year of no Job, back to SEC , I decided to leave Sri Lanka. Many other Engineers have left for good. When I left for Australia in 1973 I found that there were only a few Sri Lankan Engineers, within Australia, who could be counted with your fingers, But today one finds Sri Lankan Engineers in almost all Councils, Departments and Private sector spread through out Australia. Sri Lanka has lost them for good. Does the Institution and the politicians realise this fact. It is not the same as exporting our women to middle east to get their labour exploited for the politicians to run around in the latest luxury vehicles. Our women come back , with Arab babies and lots of Foreign Exchange. But this is not the case with Engineers to the developed world. How can we arrest this situation. The Institution of Engineers has to encourage the Engineers to move close to the community where they work and live. They need not associate only with other Engineers and Professionals. Where ever there are local engineering problems effecting the whole community, especially the vast majority of those silent, the data base in the institution should be used to find out the Engineers living in the Area. They should be encouraged to take the issues up and fight on behalf of the community. With the backing of the institution many engineers would enjoy working with the community for common good. Many problems faced by the community today, be it in the rural or urban sector has an engineering basis and often tackled by an Engineering Department, even though the head is an administrator. There is a good chance for the engineers living in the area to work with the community on these problems, rather than imposing the staff engineers solution through the respective department. My own experience since coming back to my home at Kohuwela in 1995 speaks for itself. Two problems faced the community. a) For many years the abandoned Quarry on our Road was used to dump Garbage from Dehiwala ÐMt Lavinia. This created a situation where the community faced problems of health and contamination of water. The smell of the dump effected a radius of more than 2km. b) Due to filling of the paddy field land in an adhoc manner with disregard to SLLRDC plans and specifications many residents were flooded out of their homes. Been a former Peoples Committee Chairman in the early 1970 and a resident of Kohuwela I was approached by the effected community to form an organization to deal with these two problems. WE formed the Environmental Association Kaubowila East of which I am the President. We effectively stopped the garbage dump and gave the alternate Environmental solution to the garbage problem. ie Reduce Reuse and Recycle. We have developed a recycling of garbage to compost bin 'GARBY' which has now been installed in 350 locations including the Institution of Engineers premises, with UN assistance. We have united with the citizens of Alupotha Hanwella to stop the World bank funded garbage dump, which would take 1500tons of garbage a day from Colombo to this picturesque valley, threatening the water supply to Colombo. Process your garbage in your own Backyard is our solution. On the issue of flooding with constant reminders and often public demonstrations We were able to stop the filling of the paddy field. We came close to breaking the Law, for the community good. As laws are often drafted and used for the benefit of the politicians, and their chuck golayays, Engineers should not be afraid of breaking the laws if the authorities responsible are reluctant to implement their own laws. We found this situation with the SLLRDC who are reluctant to carry out their function to protect the community from floods. Under various pressures the SLLRDC leadership who are Engineers were found to be weak in taking necessary action on illegal filling of channels , and wet lands. In both issues we had to deal with Politicians who used the engineers in the departments as serfs. By engineers taking the cause of the community We were able to give the necessary strength for the departmental engineers to do the right thing. Then the Institution has a role to protect those who might fall foul of the politicians when doing the right thing. As I found myself in the hands of politician Mr Keuneman in 1970. My wife was expecting our first baby and I was out of a job. This is the plight most public servants are facing today in trying to do the right thing as well as protect the family, from the economic hardships. May I suggest, that the Institution can commence a fighting fund or an insurance scheme to protect those who fall foul of the political system in trying to do the right thing by the country, not the minister or the politician. Such measures would develop the confidence of our engineers , who can be assured that their is an institution like a mothers hand to protect them for the common good. Let us do it in the new year. As your Honorary Secretary such ideas can only be implemented if there is greater participation by the members. Other view points on this aspect of greater community standing for the engineers is most welcome. Such standing will certainly reduce the drain of our engineers to serve other parts of the globe, as they are assured of community acceptance within Sri Lanka. A truck-load of concrete please! "String hoppers with fish curry'. It's that easy to order. However, when it comes to ready-mixed concrete, you can't just place your order, stating 'A truck-load of concrete, please'. First you should check if ready-mixed concrete is economical for your construction. Determine what type of performance you expect from the concrete, and how much you need. You should also know how to find a ready-mixed concrete producer delivering quality stuff. And to maintain quality, what standard tests are involved. What's more, as the purchaser, you should know your responsibilities and, above all, what should be done in a dispute. A single document would provide all the information: SLS 1144: Part 1: 1996. Specification for Ready-Mixed Concrete. • What is ready - mixed concrete? • Advantages The site may be too small for a site mixing plant to operate. In fact ready-mixed concrete may be the only option available. A site mixing plant consumes various costs: operating, maintenance and manning. Still it would seldom work continuously to its full capacity. In fact if concreting takes place in huge amounts or concrete is done now and then, ready - mixed is better. In the former case, a site mixing plant may fail to cope with the demand; in the latter, it would be idling most of the time. Besides a mixer truck can be directed to discharge concrete at different parts of the site. Distribution of site-mixed concrete wouldn't be that easy. Finally, when ready-mixed concrete is used, rejection of unsuitable concrete would be cheaper and more convenient. • Disadvantages How much concrete is needed should be calculated, not roughly, well in advance of delivery. The site may require telephone facilities - especially for cancellation of an order, which should be done well in advance. Maintaining workability of fresh concrete upto the placement stage is difficult, and demands close attention and admixtures. Besides mixer trucks need suitable access to reach the location where concrete is to be placed. The ground should be strong enough to support their heavy load. Delays in delivery may occur due to traffic jams, accidents or break-downs. So the concrete placement gang would idle and site progress would be disrupted. Another problem occurs when an unsuitable concrete load is rejected. The subsequent delay may adversely affect the previously placed concrete. • Materials * Cement: for normal concrete Ordinary Portland Cement (OPC) conforming to SLS 107 is used. Special concretes, however, need special cements: for large pours (eg. dams), low heat portland cement (BS 1370); for concrete exposed to sulphate attack, sulphate resisting portland cement (BS 4027); for early removal of shutters, rapid hardening portland cement (BS 12). If possible, cement should be obtained from a single source. That is to avoid undue variations. * Coarse aggregate: In Sri Lanka, crushed stone. Usual maximum dimension is 20 mm; if no restrictions, can be as high as 40 mm. However, it may fall to 10 mm in cases of thin concrete sections, small cover or congested reinforcement arrangement. * Fine aggregate: usually, river sand. Washing may be needed if sea sand is used. Finely crushed stone can also be used. * Water: Potable water should be used. Coloured or smelly water should be avoided - especially wash water from the mixer. Excessive water reduces strength. So no water should be added after initial mixing. If workability is lower than required at the time of delivery, water may be added with care - especially if there is a maximum water-cement ratio. * Admixtures: Chemicals added in small amounts to gain special properties such as delaying the setting of concrete or improving workability without adding water. • Types * Truck-mixed concrete: Only one such supplier in Sri Lanka. After delivering solid ingredients into a truck-mixer, water and admixtures are added. Mixing is entirely done in the truck-mixer, during the journey itself or after arrival at the site. * Shrink-mixed concrete: Not practised in Sri Lanka. First, mixing is partially done at a stationary mixing plant and the remainder of the mixing operation done in a truck-mixer. Suitable for long hauls. • Producer's responsibilities • Measurement In the designed mix the purchase specifies the required performance of the concrete; the producer, selecting suitable mix proportions, produces it. Testing for strength is essential for compliance. * Basis of supply In general designed mix is cheaper, producers have ready-made designed mixes for various strength grades. If, however, both types are equally priced, the better choice is the prescribed mix - especially for small scale work. Checking would be easier and, above all, there may not be much time to collect data to support mix design proposals. • Purchaser's responsibilities Once the delivery is complete, wash out facilities should be provided at the site. Normally, a truck should be released within a half an hour; a longer period due to purchaser's fault may result in a charge for waiting. • Delivery Two site factors affect the delivery rate: methods of placement and compaction to be adopted. Most local producers can handle delivery rates upto 60 cubic metres per hour. A truck mixer can discharge at a rate of 0.5 cubic metres per minute, or the entire load in 5 minutes. Usually discharging should be complete within ninety minutes or 300 drum revolutions since batching. In a hot climate like ours, it may be sooner than this; however, using admixtures, this limit can be extended. Ready-mixed concrete should be transported from the mixer to the site as rapidly as practicable and deposited close to its final position. All this should be done while maintaining the required workability and preventing two things: loss of any ingredients and introduction of any foreign matter (especially more water). • Testing A sample should not be taken too early or too late; that is, before 10% or after 90% of a batch has been discharged. The sample should be sufficient to conduct all tests required by the specification, and it should be collected from a moving stream of concrete. The rate of sampling depends on the type of structural element: for columns and contilevers, one sample per 10 cubic metres or 10 batches, whichever is lesser; for beams, slabs and walls, one per 20 cubic metres or 20 batches. These tests should be done: 1. Slump Workability, or the ease with which concrete can be handled and placed, is measured by the slump test; it should be completed within 15 minutes of receipt of concrete at the site. The slump value is used as a limit for various purposes: for example, to use truck mixers, a minimum slump of 50 mm is needed; to pump concrete, 100 mm is the minimum. Test for mix proportions is done by analysis in a laboratory. So the sample should be placed in a clean, air-tight container, which should be sealed within 5 minutes. If test results indicate that concrete fails to conform to specification, the cost of tests should be borne by the producer. If all is clear, the purchaser should foot the bill. • Pumping of concrete Special preparation is a must for pumping. When compared with normal concrete, the sand content in concrete to be pumped should be slightly higher (upto 4%). The minimum cement content, 300 kg per cubic metre; maximum aggregate size, one third of the pipe diameter. Workability is more important. In addition to retarders, such concrete needs water reducers or superplasticisers. • Disputes Suppose the strength of concrete is lower than required. If it affects the durability of concrete, removal and replacement is unavoidable. Suppose the reduced strength satisfies durability requirements. The lower strength may still be enough to carry the design loads; then, no problem. However, if the available strength isn't enough, alternations like enlargement of sections or provision of additional columns or walls may be necessary. Suppose the durability is sufficient but the available strength is far from enough, or alterations are not practical. Then, removal and replacement is the only option. In a dispute, apart from costs of alterations, removal and replacement, more costs come to play: costs of delays, inconvenience, additional tests and experts. If talks between the two parties fail, arbitration is necessary. A panel of three engineers is chosen: one nominated by the producer, another by the purchaser and the third agreed upon by both these engineers. The decisions reached by the panel are binding, except modified by a court. The panel would decide who should bear the additional costs. An alternative to this panel is an arbitrator nominated by the IESL (Institution of Engineers Sri Lanka). (Written by Asitha Jayawardena based on a lecture delivered by Professor S. R. de S. Chandrakeerthy of Moratuwa University, at the monthly event of 'Question Time' organised by the Society of Structural Engineers, Sri Lanka.) From the book 'The Palm of His
Hand' by E.C.T. Candappa
Continued from yesterday Older sister in both Sinhala and Tamil was akka, while in Sinhala younger sister was nangi and tangachchi in Tamil. Tangachchi sounded like a succulent fruit too. He asked the lad how he was, and he said that "it" hurt a little, and added philosophically that it could not be helped. Not a word or even a note of complaint. He wondered again: was it possible for people, even a child bred in a soil of spoilage to change so much and so soon for the better? Well, this one had, and here was evidence before him. How much people depended on prejudice and theories cooked by jaundiced pundits. Every person was unique, as indeed was every spark of Grace. Chapter 30 If one had gone to the extreme of employing an ugly name like conspiracy to describethe feeling in the air one would not have been wrong. But it would have been of the genteel kind associated with office birthday surprises or the decking of the Christmas tree with gifts. It was a benign conspiracy from the feel of it. There was so much of it, subdued though it was, that Raj and many of the other patients could not sleep. Even the ancient Haniffa’s feet were wagging vigorously under his bed sheet. Raj’s immediate neighbours, Patil and the schoolmaster, were awake, beady-eyed. As usual lights were out by nine. Corridor lights were on, as usual, all night, and in their haze Raj could see nurses gliding past evidently in rubber-slippered feet. Finally, to put them all out of the misery of expectancy, Miss Andradi, the tall, dark, red-lipped nurse, came into the ward and whispered at each bed, "Come to the next room. There’s a surprise." Raj, Jayawardene, the school teacher and the young clerk trooped out. The next room was bustling. People were walking about and talking but in whispers. Soon it became evident that the centre of the activity was the bed of the long staying cancer-patient, Mr Weerasinghe. There he was sitting up with two pillows propping him up, his face flushed with excitement accentuating his halo of white hair, serving string hoppers out of a large pan to plastic plates of different colours. Around him also were deep dishes from which he served the usual accompaniments for string hoppers: steaming hot white coconut soup, the highly seasoned red coconut sambol, and that delicacy over all delicacies, the seeni sambol. There were also small fricadels and large pieces of fried fish. The string hopper is prepared by pressing out a very thick batter through a mould with a perforated metal disc, so that several dozen noodles emerge, falling on a round frame while the mould is moved in a circular direction. Several such are steamed over a pot and then the palm sized hoppers are collected. Just with a thin coconut soup and the red coconut sambol, it is a sought after meal. But Mr Weerasinghe’s spread constituted a feast such as would be provided on a special occasion. Every month, on a Saturday night, Mr Weerasinghe celebrated his presence in the ward, a celebration of life. He was dying and he knew it, and everyone else knew it. And he took each day as a reward and a month as a bonus. And he thought it fit to share his jubilation. And the nursing staff, used to the presence of death, participated in this man’s defiance of death for it seemed that he parried decay by his aggressive assertion of life. They believed he ought to have died months ago. Mr Weerasinghe was the essential Ceylonese host, not happy until everyone had eaten a little more than their current appetite allowed. "Have a few more; what about some more fish?" "I’m quite happy now." "Oh, come on, you’re a young fellow. At your age..." The schoolmaster was seated on the edge of a bed and eating with breath-taking gusto, customary rustic relish and concentration. This was precisely the kind of meal he would have relished. He ate with his fingers as the great majority did. The Western educated elite who probably had lived in England for some time, and their families, adopted an occidental lifestyle. They ate Western styled food and used Western cutlery and crockery. The village headman was glad to note there were no eggs. Nor were the patients who were still unable to leave their beds in other rooms neglected. Plates were passed round with exaggerated quiet and the feast was enjoyed by all in varying degrees. When a basic Ceylonese, that is to say one untouched by foreign ways, ate a meal, there was little time for conversation. While a mouthful was being masticated, the other mouthful was being manufactured on the plate. And as the first went down the gullet the second was hastened to the waiting wide-open mouth. A really hungry Sri Lankan with a healthy appetite attacking a standard Sri Lankan main meal of rice and curry was a truly awesome sight. The highly seasoned food would in a few moments make the diner perspire freely, and this, plus his avidity and concentration made his eyes tear and bulge and his nostrils dilate. A stranger might wonder at which moment he would bite his fingers off, and likewise admire the adroitness with which he would shovel the food in and then take the fingers away a second before the jaws clamped down. The women, vive la difference, ate daintily and with quiet enjoyment. The schoolmaster rose, his face flushed with the exertion and the heat generated by the chilli in the curries, went up to a sink and washed his hands and his plate. He then found the time to smile expansively and belch aloud. "Maru," he said, a single word of approbation uttered with conviction. There were similar notes of satisfaction all around. For a single moment frozen in time one point of the universe was suffused with one man’s urge to live. It was past one when Raj returned to his ward. Sleep had escaped him while he was away. He sat up with his back to the bed-head and resumed his diary. About two o’clock Jinasena, the trade union leader entered. He looked awake and alert, a man accustomed to long hours and hard work. (c) E. C. T. Candappa Continued on tomorrow |
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