|The Use of Selected Indigenous Building Materials with Potential for Wide Application in Developing Countries (HABITAT, 1985, 80 p.)|
|III. CONSTRAINTS LIMITING THE ADOPTION OF INDIGENOUS BUILDING MATERIALS|
32. Despite the favourable factors for promoting indigenous materials, there are some constraints which limit the widespread production and use of such materials. In some countries, the problem is related to inadequate production capacity or the low level of demand for indigenous building materials, but, in other countries, the problem is that there is hardly any available local experience of the production and use of such materials. However, there are some constraints which are basic to most developing countries and are responsible for the inability of indigenous materials to make an impact on the building materials industry. These constraints are related to, at least, five issues, namely: (a) technology of production; (b) investment requirements; (c) quality of output; (d) demand for indigenous products; and (e) inappropriate use of materials in construction.
33. A prerequisite for commercial production of indigenous building materials is that the technologies involved be tested, proved and, above all, widely known at the local level. Although there is an international flow of information on some innovative technologies, this has not developed to the level where such technologies can readily be replicated from one country to the next. In fact, it can be argued that, although the technologies in question are not completely new, there are not many organizations which have established themselves internationally as technology suppliers in the field of indigenous materials. In India, for example, the Cement Research Institute has been responsible for developing and licensing both rice-husk-ash-cement plants and mini-plants for cement production, while the Khadi and Village Industries Commission has been active in establishing lime and lime-pozzolana production units. Outside India, there are not many known organizations with comparable experience on promotion of technologies for low-cost binders at the local level.
34. Even if an information flow on innovative technologies is achieved, the process of actual development and commercialization of a newly introduced technology is complex and resource-consuming. This acts as a deterrent to promotion of innovative technologies. The transfer of technologies from one country to another is often facilitated if the new technology is similar to locally available production techniques. However, in some cases, a country receiving an innovative technology has to devote resources to training in a variety of skills, to building physical infrastructure, to undertaking extensive demonstration programmes, and to purchasing tools and equipment. In many developing countries, the government may not be able to afford this cost of technology transfer, and, in the absence of governmental support, there is hardly any alternative means at the local level of covering the initial cost of technology transfer and development.
35. In some countries, the main factor limiting the flow of technology is not so much related to defects in the transfer of technology at the international level but, rather, related to the inability of local institutions to translate successful research findings in appropriate technology to commercial-scale operation and to the use of the self-help builders. There are cases where technologies for production of low-cost materials have been developed by a local agency based on indigenous factor inputs, yet these findings have not been demonstrated on an extensive scale or replicated by any other agency.
36. When an innovative technology has finally been transferred from one country to another, the task of commercial-scale adoption of the new technology in the recipient country depends largely on how some basic constraints to investments for building materials production are tackled. For instance, access to raw materials could be a serious factor inhibiting local investment in indigenous building materials production. Most of the technologies for production of low-cost materials are appropriate at the small scale, with the advantage that they can utilize small deposits of raw materials for their operations, yet it is precisely the small deposits or of raw materials which are often neglected in most countries. Information on small-scale deposits of raw materials, such as clay, limestone and gypsum, is hardly available at any local agency. An investor would typically like to have full knowledge of raw-materials deposits, in terms of the quantity available and the suitability of the material for production. This often involves extensive pre-production tests which are costly, and normally a small-scale entrepreneur would avoid such pre-investment costs.
37. The inaccessibility of raw materials could be due to the lack of access roads to the source of raw materials, and, again, the high cost of providing such basic infrastructure could deter local entrepreneurs from investing in the indigenous building materials sector. Sometimes, an access road to the source of the raw materials may be available, but a suitable site for locating the production plant may be too far away from the source. For example, the lime-pozzolana industry in Rwanda exploits limestone deposits from a source five kilometres away from the factory, while the pozzolana is derived from a volcanic ash cone located about 40 kilometres from the production plant. In most countries where the transport infrastructure is underdeveloped and fuel costs are high, the distant location of basic inputs for production may easily frustrate efforts in promoting wide-scale production of indigenous building materials.
38. The use of agricultural residues, such as rice husk for production of pozzolanas and coffee husk as a source of fuel in building materials production, is an important innovation which can have an impact on cost reduction of local building materials. However, the cyclical nature in which they become available can pose a limitation to the production process. If such agricultural products are to be used in the production process, it is desirable they be available throughout the entire duration of the building materials production cycle which may extend far beyond the period when farmers harvest their agricultural produce.
39. For this reason, an investor may have to purchase large quantities of the agricultural residues at the time they are available and hold them in stock. A small-scale investor will require credit for working capital, in order to ensure a planned output. In most developing countries, there are hardly any effective credit facilities for small-scale entrepreneurs.
40. The overall capital requirements for the production of most indigenous building materials are relatively low and can often be met within the limitations of developing countries. Materials such as lime, bricks and several pozzolanas can be produced with almost all the capital requirements being met from local sources. In a review of country case studies on promotion of indigenous cementitious materials,4/ the investment was found to be as low as $2,500 per 1,000 tons of annual production in the case of gypsum plaster production in Cape Verde. This level of investment was very reasonable in comparison with an amount of $120,000 to $200,00 required for the same output in a conventional cement plant. Even though the capital requirements for production of indigenous cementitious materials are low, the small-scale investor may be even more limited in access to capital. Sometimes, basic capital inputs are not available on the market, and, where the production process is dependent on imported equipment, such as a ball mill to grind the pozzolana, the constraints in foreign exchange supply and the intricacies of import licence allocation may be impediments to the small-scale investor.
4/ See annex I.
41. There is a diversity of available technologies for production of most low-cost materials, but the choice of a particular technology should normally be determined by the type of raw materials to be used and the available forms of energy. In general, the quality of output will depend on the choice of an appropriate technology, given the fact that raw materials will vary in their characteristics from one location to the next. There is always the danger of attempting to adapt one standard technology to different situations, and this can be the single cause of low-quality production.
42. Small-scale labour-intensive technologies for the production of low-cost materials have the advantage of being able to function using small deposits of raw materials, often of an inferior type. However, this advantage could, at the same time, be the cause of an unsatisfactory end-product. For example, for most indigenous cementitious materials such as lime, gypsum and rice-husk-ash, the quality of the parent raw material which is used for production is a significant determinant of the quality of the final output. For this reason, a clear understanding of the basic properties of the raw material is essential to the entire production process. However, the predominant practice in the production of most indigenous cementitious materials is that the quality of raw materials is taken for granted and assumed to be standard in all cases, so that differences from one deposit to the next are not accounted for in production. The main constraint here is that the level of skills of those using the raw material for production is inadequate, but a fundamental problem is that, even if they acquire the requisite skills, they still have to contend with lack of access to the appropriate tools for identifying the production characteristics of the raw materials.
43. The quality of most building materials which are popularly adopted in construction is promoted through a set of nationally or internationally accepted standards. In most countries, materials, such as Portland cement, steel and glass, are produced to conform to such standards. While standards are a desirable mechanism for regulating quality of production, the first and foremost requirement in achieving this objective is to ensure that standards are available for the types of materials which require quality control. However, in most developing countries, there are hardly any standards for indigenous building materials. Standards institutions are available in several countries but they lack the capacity to deal with the requirements of the indigenous building materials sector.
44. For a few indigenous products, such as fired-clay bricks and tiles, there are opportunities to adapt available international standards to local situations. However, the majority of indigenous materials, such as lime-pozzolana or rice-husk-ash-cement, are relatively new, and there is no basis for adopting a foreign standard. It is likely that, apart from India, where standards have been formulated for a variety of lime-pozzolana mixtures, there are no established standards.
45. Because indigenous raw material sources vary in composition and properties, it will be difficult to formulate one standard for uniform application in a country. For instance, standards for lime will have to be formulated covering a variety of raw material sources. In the same way, standards for lime-pozzolanas available in a country, and the options available for different mixes and for different uses of the final product. This alone is a resource consuming exercise which many countries cannot afford.
46. Even though standards are the basic framework for promoting quality production, they are only effective if properly enforced. However, the enforcement of standards presupposes that manufacturers have acquired the appropriate production techniques to be able to conform to principles of quality output. Because indigenous materials are relatively new on the market, there is likely to be a gap between standards and actual field production practice. In addition, the production processes for a variety of indigenous materials can be relatively intricate even at the smallest scale of production, requiring several intermediate processes, a single one of which could be the source of low-quality output, if not properly dealt with.
47. For instance, in the production of lime at the cottage scale, efforts in identifying good quality limestone, preparing the appropriate clamp kiln and good firing and slaking of the lime, will all be undermined if the final product is not properly stored. Particularly, for small-scale producers, there is always the disadvantage of their being predominantly illiterate, so that standards will tend to be too technical and incomprehensible to them. Similarly, the formulation of any set of guidelines to ensure adherence to standards of production will have to take into account the constraints of disseminating information to the small-scale producers.
48. The wide adoption of indigenous building materials depends to a large extent on market conditions, i.e., a large and sustained demand for construction materials. In fact, it can be argued that constraints which limit the adoption of indigenous materials are related to the demand for the products rather than to the production or supply of the materials. The cost of indigenous products in relation to other comparable materials on the market is an important factor of demand.
49. Thus, demand for indigenous cementitious materials will largely depend on their market prices in comparison with the market price of Portland cement. Very often, the market price of indigenous cementitious materials, such as lime and lime-pozzolana, is high or unattractive, when compared with that of the popular and established product, Portland cement. This is a serious limitation, especially with regard to the fact that the indigenous cementitious materials are meant to be low-cost products.
50. One reason why indigenous cementitious materials are expensive - sometimes more so that Portland cement - is that the latter product often enjoys subsidies of one form or the other. The effect of import subsidies, foreign-exchange rates and related measures can be to make imported factors of production less expensive and, therefore, more attractive than indigenous products. Similarly, through certain trade policies, the directly imported Portland cement can become less expensive than indigenous cementitious materials. Sometimes, even though the cost of production of a unit quantity of Portland cement is higher than that of an indigenous binder, governmental price controls on Portland cement can lead to imbalances in the market situation, thereby making indigenous products far less attractive.
51. Even when indigenous building materials are attractive in terms of market price, there is still the problem of consumer biases against the products. Preference for Portland cement, as against lime or lime-pozzolana, may not be based on considerations of cost or quality but based on non-quantifiable factors of taste or values. In most cases, preference is given to Portland cement and such imported materials for the simple reason that existing building regulations tend to support their popular use in construction. In addition, the inflexibility of building regulations has meant that relatively new materials, such as indigenous cementitious materials, cannot be incorporated in the regulations.
52. The failure to use indigenous materials in government-sponsored construction projects is another serious constraint which limits the wide-scale adoption of the materials. Governments in developing countries are often the single largest client of the construction industry, so that they limit the popularity of materials by not adopting them in their projects. In many countries the regulations and high standards set for government-sponsored buildings inhibit the use of indigenous building materials. Normally, government-sponsored construction projects are accorded a high status symbol in low-income settlements, and promotion of selected building materials is facilitated when they are used in governmental projects. However, indigenous cementitious materials, for example, are yet to have an impact on governmental construction projects, for which reason the remainder of the construction market, notably the low-income shelter segment, accords a low preference to such materials. In most countries, procedures for tendering and awarding contracts for government-sponsored projects prohibit the use of binders others than Portland cement, so that, even where there is a preference to use indigenous cementitious materials, it simply cannot be followed.
53. The lack of requisite skills or techniques in the appropriate use of indigenous building materials in construction could be the single most important factor limiting the wide-scale adoption of such materials. Construction skills are important to the extent that they are linked to the objective of achieving minimum cost of indigenous building materials. An indigenous building material can be sold at a low cost on the market; however, where skills are deficient or where there is a shortage of the requisite skills, the overall objective of low-cost construction will be defeated, because of the excessive use of materials in construction or simply as a result of the prohibitive cost of labour in construction.
54. The basic skill requirements for construction, especially for low-income shelter, are simple and relatively easy to acquire. For example, the use of lime or lime-pozzolana as binders for masonry construction is fairly simple, and skills can be acquired over a relatively short period. Despite the simplicity of using these materials in construction, it still requires some basic training to ensure that skills are available on the market. In most cases, skills to use indigenous materials in construction are taken for granted, on the assumption that locally available skills can be adapted to all situations in the construction market. However, some indigenous building materials are relatively new to local craftsmen and, in the absence of any special training programmes, these materials will remain unpopular.
55. Safety of construction and durability of indigenous building materials depend to an extent, on the competence of the labour force in construction. Where skills are deficient, good-quality products could be wrongly applied in construction, thereby leading to unsafe and non-durable construction and, consequently, making a particular set of building materials unpopular. Most indigenous cementitious materials, for example, are vulnerable to this type of shortcoming and can easily become unpopular as a result of wrong application in construction. Possible areas of error are that lime-pozzolana mixtures for masonry work could be prepared in the same proportions as for Portland cement mixtures, or, the setting time for lime-pozzolana masonry could be assumed to be similar to that of Portland cement, thus resulting in non-durable and unsafe construction.
56. In construction practice, safety principles are often promoted through building codes. Codes of design and codes of construction for various elements of building provide elaborate technical details which guide the local labour force in achieving safe and durable construction. In most developing countries, building codes hardly exist and, where they are available, they are restricted to imported codes of practice for reinforced concrete technology, and, almost invariably, Portland cement is the only binder which such codes make reference to. For instance, codes of practice for brickwork, foundations and soil stabilization, as well as for concrete products, such as blocks, pipes and precast units, specify the materials to be used in such a way that only Portland cement can be used. For this reason, the contents of existing building codes can undermine the safe application of indigenous cementitious materials and, thus, limit the adoption of the materials in construction.