The Effect of Quarry Dust Concrete over Red Soil Medium as Sub-Base on the Structural Performance of Dwelling House Ground Floors

Abstract

This research sought to establish the effect of quarry dust concrete and the underlying subsoil medium on structural performance of dwelling houses ground floors. The research work was geared towards sustainable construction by using locally available materials which are eco-friendly. Housing being one of the basic needs, but its cost is beyond reach of many especially permanent housing. And in conventional construction of the floor bed in this country, even where raising of the levels is not required, hardcore filling is normally done as a sub-base just the same way a paved road would be done, not bearing in mind the difference in loadings between a road and a building floor. The aggregates in use were classified as the conventional 20 mm volcanic rock, graded 5-14 mm, non-graded volcanic rock quarry dust and Nairobi sedimentary rock quarry dust besides river sand and red soil(sandy silty clay with traces of gravel). All the material properties were determined to British and American standards . Concrete slabs class 15 (1:3:6 nominal mix) of one meter squared but in thickness of 150 mm and 100 mm, three each for the various aggregates were cast, cured for 28 days and tested over red soil compacted to maximum dry density by loading on loading jacks for compression and strain on their surfaces through strain gauges attached to a data logger. The hardened concrete from the various aggregates was further tested for compression in a compression machine on concrete cubes cured for 28 days. Another very important parameter of a floor, water seepage was also put to test for the various concrete aggregates. The cured concrete from the various aggregates were subjected to same water heads in special designed containers and water percolating measured by scale rule. All the aggregates were permeable after testing for 28 days, all allowing up to between 16 mm and 20 mm of water passage under the same conditions with the smaller sized aggregates allowing in more water than the single sized 20 mm volcanic rock aggregates which was the largest size used in the research.