Study on preparation of brick blocks by using construction waste and sludge.

The demand for scarce raw material has been increased with rise of construction. An ideal raw material is clay, which is abundantly used in manufacturing bricks. The proposed study aims at making a brick blocks with clay-free materials. Therefore, instead of clay, waste additives such as sludge waste, construction and demolition waste, and fly-ash are used as a binding material. These additives would contribute a better performance and properties without altering the desired strength. Sewage sludge is an important component of sewage disposal, but it is also ruinous to the environment. Construction and demolition (C&D) debris are a rising source of waste utilization. The objective of the proposed work is to eliminate the natural resources like clay and utilization of waste additives effectively in making brick blocks. The mix proportions are maintained at 30% sludge with 3:2:2, 2:3:2, and 2:2:3 (fly ash: cement: C&D), similarly, 40% sludge with 1:3:2, 2:3:1, and 3:2:1 and 50% sludge with 2:1:2, 2:2:1, and 1.5:1.5:2. The physicochemical properties include density, water absorption, pH, shrinkage, plasticity index, and efflorescence, and leaching characteristics were analyzed. Mechanical properties include compressive strength and thermal conductivity; mineralogical and microstructural analysis and durability aspects were carried out. The presence of organic matter influences the overall property. The stress distribution was induced by porosity and attained a maximum strength of 14.5 N/mm. Durability was influenced by compaction and temperature. At high temperature, the particles are well compacted. The concentrations of heavy metals are immobilized. Based on the above, it can be practically implemented in structures as well as in hidden masonry works.