The effect of water/cement ratio and vibro-compaction on the compressive strength of reconstituted limestone

Abstract

Waste material generated from the construction industry is a major threat to our environment. However, this waste has the ability of being recycled and reused in combination with other building materials, thus minimizing the production of construction waste. The fabrication of a masonry composite building material, consisting of limestone powder produced from crushed blocks or quarry waste, is currently an ongoing project at the University of Malta. The process of creating this engineered stone involves the mixture of mainly limestone powder, cement and water, which can be produced as either blocks, cladding or paving. Former research focused on the generation of compressive strength by compacting the material in order to expel excess water, which results in a dense material. The current objective of this project intends to explore the variation in compressive strength with varying water/cement ratios in the absence of a compaction load. This is achieved by means of a large batch sampling with varying water and cement contents, and vibration times. The workability of mixes containing a constant high water content and varying cement contents, is investigated with respect to mixing time. The research aims to provide a more comprehensive understanding of the factors influencing the compressive strength of reconstituted stone, which will enable further optimization of the mix, leading to the production of the building block.