Experimental study on the use of marrum (laterite gravel) for improving crushed construction waste used in backfilling.

Abstract

The construction industry involves constructing or erecting buildings, structures or infrastructures. During the course of construction, many kinds of materials are used; both organic and inorganic materials. The residues or wastes from the organic materials decay to form soil while the inorganic materials pollute the environment when poorly disposed. Wastes from demolition of structures also contributes greatly to the environmental degradation. As professionals from the Built Environment, we can find the best and sustainable way to hand such wastes. These construction wastes can be used during backfilling. However the crushed construction wastes do not have enough plasticity to consolidate adequately when compacted. This meant to opt for a material which can improve the properties of the crushed construction waste hence laterite gravel which is considered a good backfilling material is used. Therefore, this led to the need for further studies using the different variations of these two materials. A literature review was conducted to establish the properties of the backfilling material and to select the best test to make the research successful. The tests were then carried out from the Makerere Highway Laboratory and the results were analyzed and presented in this report. The test considered five points; the neat crushed construction waste, the neat laterite gravel, the sample with 20% laterite gravel, 40% laterite gravel and the sample with 60% laterite gravel. After analyzing the results obtained from the study, various conclusions and recommendations were drawn. The research concludes that the composite sample with 20% laterite gravel and 60% crushed construction waste contains more preferred properties as the best backfilling material. Hence the cost benefit ratio is calculated for the construction manager using this composite backfilling material. Finally the construction waste will have a safe and beneficial disposal without causing environmental degradation.