Research article

The initial setting time and compressive strength of Sandcrete Blocks made with Gmelina Leaf Ash (GLA) as a partial replacement for Cement
 

^*1Chiemela Chijioke, ²Chukwudi Prince EU and ³Jennifer George

^1,2Department of Civil Engineering, Federal Polytechnic Nekede, Owerri, Nigeria

³Department of Architecture, Taraba State Polytechnic, Suntai Jalingo, Nigeria

 *Corresponding Author: cchijioke@fpno.edu.ng

       Received 03 October, 2024                 Accepted 20 November 2024                  Published 24 November, 2024 

Abstract

This research study focuses on the assessment of the initial setting time and compressive strength of sandcrete blocks made with Gmelina leaf ash (GLA) as a partial replacement for cement. The aim of this investigation is to explore the potential use of Gmelina leaf ash as a sustainable alternative to conventional cement in sandcrete block production, with the objective of reducing environmental impacts and construction costs. A total number of 18 blocks were produced using 6 different mix ratios by replacing GLA with cement. The initial setting time test were carried out for the different mixes in order to ascertain the effect of GLA on the initial setting time of the sandcrete block. The bocks produced were cured and crush, afterwards the optimum mix ratio and compressive strength of the sandcrete block were obtained. The chemical properties of the ash obtained were similar to those of some pozzolans. Hence, the GLA can be considered a pozzolan. The compressive strength and initial setting time test results were carried out on the sandcrete blocks. Blocks were produced with GLA as a partial replacement to cement for a mix ratio of 1:6. It was observed that the compressive strength reduces slowly as the percentage replacement increases until 30% replacement, and then a high reduction was observed in the compressive strength from 40% down to 50% replacement. For the initial setting time results, the initial setting time increases as the percentage replacement increases. It can be seen that the compressive strength value of sandcrete block produced with SGA as a partial replacement for sand gave the maximum compressive strength values of 3.46N/mm² and an optimum compressive strength value of 3.0 N/mm² at 30% replacement. It can also be seen that the initial setting time follows a straight-line pattern with the percentage replacement, the initial setting time increases as the percentage replacement increases.

Keyword: Gmelina leaf ash (GLA), Sandcrete block, Setting, Compressive strength