Behavior of Self-compacting Mortars Based on Waste Brick Powder

Abstract

Aims: Study the performance of self-compacting mortar (SCM) using waste ground brick as cement replacement material. Background: Large amounts of brick waste are produced in brick manufacturing plants and construction and demolition sites. The use of these bricks as partial substitution to natural aggregates or after crushing as fines for partial cement substitution could contribute to reduce the problem of waste storage and environmental pollution as well as in the conservation of natural resources. Objective: The objective of this paper is to study the effect of adding waste ground brick on the performance of SCM at the fresh and hardened state. Methods: It is an experimental investigation where mortar specimens where cement was partially substituted by crushed recycled bricks fines recovered from a brick plant. The level of substitution was either 0%, 5%, 10%, 15% 20% and 25% by weight of cement. Workability was measured by slump flow and flow time by V-funnel test. Compressive strength and water absorption by capillary were measured on 40x40x160 mm3 prismatic specimens. Results: The experimental results show that self-compacting mortar can be obtained up to 25% of cement substitution by brick powders. The compressive strength was improved at long term for up to 15% cement substitution by brick powder. The sorptivity coefficient is increased by incorporation of brick waste powder. Conclusion: The substitution of cement by waste ground brick powder up to 15% of waste brick powder has little influence on the rheological parameters of self-compacting mortar and the compressive strength is increased at the long term. Further investigations are underway to study the shrinkage, the long term durability and the pore size distribution by mercury porosimetry.