This research aims to evaluate the strength development and microstructure of a green
mortar produced from waste red brick powder (WRP) as a partial cement replacement. The
mortar samples were prepared with various WRP content of 0%, 10%, 20%, 30%, and 40% of
total binder weight, and the w/b was fixed at 0.4. The fresh properties were checked by
flowability and fresh unit weight. While the compressive strength was conducted up to 28 days.
The mortar samples exhibited a reduction in flowability and unit weight with increasing WRP
content. The incorporation of 10%-20% WRP improved the compressive strength of mortar
samples at 28-day, while the compressive strength reduced with higher WRP content (30%-
40%). The C-S-H/CaCO3 gel, Ca(OH)2 and ettringite were hydration products of WRP mortar
samples. The incorporation with WRP significantly reduced the Ca(OH)2 content.