Performance of potato starch admixture on fresh and hardened behaviours of concrete at varied mix design ratios

Abstract

The urgency to attenuate techno-economic and ecological threats constituted by chemical admixtures has necessitated the adoption of feasible natural admixtures. The chemical interaction of admixtures with concrete ingredients affects concrete's plastic and hardened structure. The impact of concrete properties on construction works is of great concern to engineers as it plays a vital role towards viable infrastructural development. This study focused on developing an eco-friendly, sustainable structural concrete using potato starch (PS) as an admixture. PS has been included to in concrete in discrete percentages (0%, 0.4%, 0.8%, 1.2%, 1.6%, 2.0%) of cement weight employing mix ratios of 1: 1.5: 2, 1:2:4, 1:3:6 and water-cement ratio of 0.6. This study evaluates the effect of PS-admixture on concrete properties in the plastic state (setting time and workability) and at the hardened state (compressive strength) at 7, 21, 28, 56, and 90 days of curing. Potato starch (PS) admixture showed higher compressive strengths in concrete mixes with lower ratios (1:2:4 and 1:3:6). The strength test results for the 1:1.5:2, 1:2:4 and 1:3:6 mix ratios show a maximum strength of 32.77 N/mm2, 35.12 N/mm2 and 38.97 N/mm2 respectively for 28 curing days, at 1.2% PS addition, after which there was a strength-reduction. Rise A rise in the percentage inclusion of PS boosts the setting- time of cement paste and compressive strength. An optimal- percentage of 1.2% PS by cement- weight is advised for reliable concrete strength performance. Utilization of PS in concrete is recommended and should be embraced, considering its low- cost, availability, environmental amicability, and ability to enhance structural durability.  

Keywords

• concrete
• mix ratio
• admixtures
• potato starch
• compressive strength