Reutilization potential of lightweight concrete block powder and clay brick powder as a partial cement replacement in a sustainable mortar

The solid waste of building materials from construction and demolition is considered an important matter that should care about. Building waste materials can be recycled to lower environmental pollution and save costs and raw materials. In this study, two waste building materials were used for cement replacement; they are lightweight concrete block powder and clay brick powder. Ten mixtures were conducted. The lightweight concrete blocks powder and clay bricks powder were used to cast mortar samples in different levels (10%, 20%, and 30%) separately. Also, another group of cement replacing includes the combination of lightweight concrete blocks powder and clay bricks powder together with a 30% maximum of replacement. The slump and mechanical properties (compressive and flexural strength),in addition to water absorption, and density of hardened mortar were tested at 7 and 28 days. The results obtained presented the flow for cement mortar was lowered by increasing the percentage of lightweight concrete block powder. The compressive strength was improved by 32.4% with incorporating 10% clay brick powder while the flexural strength for all combination mixes was higher than the reference mix at different ages.