Enhancement of Indigenous Production Capacity Through an Assessment of Masonry Units Produced in Mamelodi, South Africa

Abstract

There is a dearth of housing units for the teeming population in developing countries: similar challenge is noticeable in South African’s townships such as Mamelodi among others. Records showed that Mamelodi is a large, historically designated black township in Pretoria that is situated on the north eastern outskirts of Pretoria, in the Guateng Province of South Africa with a population of about one million people. The research sought to assess masonry units commonly used for housing from indigenous producers in the township with a view to determining its strength and quality in order to enhance their output capacity. Fourty three masonry units made up of bricks and sandcrete blocks were collected from five indigenous producers in Mamelodi east; and the laboratory of the Department of Civil Engineering, Tshwane University of Technology, Pretoria. Materials used include different types of cement, aggregates, hardener and water with manual as well as mechanical equipments. Sieve analyses of the different types of sand used were undertaken in line with SABS Method 829:1994. The sizes and compressive strengths of the samples were determined according to South African standards, SANS 1215:2008 and SABS EN 197-1; and compared to specified values. In addition, materials, mix proportions and production techniques were appropriately assessed. It was observed that the types of cement used by the producers were CEM 42,5N, CEM 32.5R, CEM IV/B [V] 32.5R and CEM 32,5R. The different types of sand used as aggregates were crusher sand, plaster sand and dag sand. The water used was clean devoid of any deleterious material. Though the compressive strengths were found to be less than those specified in the standards, the sizes of the samples showed variation from the specification. However, the compressive strength of the masonry units from the laboratory of the Department of Civil Engineering, Tshwane University of Technology, Pretoria complied with the specified standard. The observed deviation of the results from the approved specification may be as a result of unfamiliarity with the standard by indigenous producers, the properties of the material ingredients, proportion of the mix, the method of compaction and other controls during placing, compaction and curing. It was also observed that the materials used by the producers were found to be from different sources, while there were variable mix proportions as well as production techniques. The knowledge available to the indigenous producers from the research on the quality of the masonry units would enhance the productive capacity of the indigenous producers in the townships.

Keywords: Bricks, Compressive strength, Indigenous producers, Production capacity, Sandcrete blocks