Properties of Self-Compacting Mortar Mixed with Ground-Recycled Lightweight Concrete Block Incorporating Fly Ash

Abstract

Recycling of waste materials in construction materials can make materials environmental friendly and also reduce greenhouse gas emissions to atmosphere. This self-compacting mortar is prepared by using waste materials from thermal power plants and construction industry, including fly ash and lightweight concrete blocks as a cement replacement. Recycled lightweight concrete blocks was finely ground by Los Angeles machine, at replacement ratios of 10 and 20 percent by weight and/or mixed with fly ash at the cement replacement ratios of 40 and 60 percent by weight. Total binder material was maintain at 591 kg/cu.m. with a water-to-binder material ratio of 0.40. Controlling flow slump in the targeted flow slump diameter in the range of 25±2.5 cm by varying the superplasticizer dosage was conducted. The workability-, fresh- and hardened- properties of self-compacting mortars were tested. The results showed that self-compacting mortar mixed with 10 percentage replacement with lightweight concrete blocks (FA0LB10) or 40 percentage replacement of fly ash (FA40LB0), the compressive strength, tensile strength, and ultrasonic pulse velocity was higher than those of the control concrete (FA0LB0) consistent to the lower water absorption results. However, when incorporating lightweight concrete blocks with and fly ash as a cement replacement at 60 percent (FA40LB20), the compressive strengths of self-compacting mortar had higher than 80% compared to the control self-compacting mortar at the age of 91 days.