Water absorption, strength and microscale properties of interlocking concrete blocks made with plastic fibre and ceramic aggregates

This study determines the suitability of using shredded waste plastic and waste ceramic powder (WCP) to produce interlocking concrete blocks (ICB). The study adopted a concrete mix ratio of 1:2 containing 20 % partial replacement of sand with ceramic waste. The compressive strength, splitting tensile strength, and water absorption of the interlocking concrete blocks were determined, after 7, 28, and 90 days of curing. The ICBs developed include mixes containing plastic fibres in proportions 0, 0.5, 1, 1.5, and 2% by weight of concrete, and a control mix with zero ceramic waste and plastic fibres. The microstructure and mineralogy of selected samples were observed using a scanning electron microscopy (SEM) and XRD (X-ray diffraction), respectively. From the result, compressive strength and splitting tensile strength of the interlocking concrete blocks increased with an increasing plastic fibre content. Also, the microscale tests revealed good compactness, and interparticle reactions in the matrix. Thus, the study recommends 2% of plastic fibre content for the production of interlocking concrete blocks.