Khan Mohammad Iqbal, Abbas Yassir M, Fares Galal, Alqahtani Fahad K
Department of Civil Engineering, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia.
Materials (Basel). 2023 Sep 27;16(19):6436. doi: 10.3390/ma16196436.
The present study examines the effects of supplementary cementitious materials (SCMs) on the flowability and strength development of binary mixes. This study was primarily motivated by the need to bridge the knowledge gap regarding paste and mortar mixes containing binary cement from a variety of performance perspectives. This study examined the flowability and strength development of binary mixes in their pastes and mortars when they contain various doses of silica fume (SF), fly ash (FA), metakaolin (MK), and glass cullet powder (GP) compared with the control mix. While the presence of SF and MK reduced workability because of the nature of their particles, the addition of FA and GP improved it to a certain extent because of the spherical and glassy nature of their particles, respectively. In addition, GP was used to compare its performance against SF, MK, and FA as an alternative cementitious material. In this study, the GP performed comparably to the other SCMs investigated and was found to be satisfactory. An investigation of the rheological properties, heat of hydration, thermal analysis, and pore systems of these mixes was conducted. Compared to the control mix, the presence of 5% GP improved the rheological properties and reduced the heat of hydration by 10%. The reduced workability in SF and MK mixes resulted in a lower content of pore water, while GP and FA incorporation enhanced it, owing to improved workability. The pore area is related to the pore water, which is directly related to improved workability. According to the following order, SF > MK > GP > FA, the strength was highest for mixes containing SF and MK, whereas, with GP and FA, there was a gradual reduction in the strength proportional to replacement level and improved workability. SF, GP, and FA can be identified as performance enhancers when formulating ternary and quaternary cementitious systems for low-carbon cement.
本研究考察了辅助胶凝材料（SCMs）对二元混合料流动性和强度发展的影响。开展这项研究的主要动机是，需要从多种性能角度填补关于含二元水泥的浆体和砂浆混合料的知识空白。本研究考察了二元混合料在其浆体和砂浆中含有不同剂量硅灰（SF）、粉煤灰（FA）、偏高岭土（MK）和碎玻璃粉（GP）时的流动性和强度发展情况，并与对照混合料进行了比较。虽然SF和MK因其颗粒性质降低了工作性，但FA和GP的加入分别因其颗粒的球形和玻璃质性质在一定程度上改善了工作性。此外，使用GP作为替代胶凝材料，将其性能与SF、MK和FA进行比较。在本研究中，GP的性能与其他所研究的SCMs相当，且被认为是令人满意的。对这些混合料的流变性能、水化热、热分析和孔隙系统进行了研究。与对照混合料相比，5% GP的存在改善了流变性能，并使水化热降低了10%。SF和MK混合料中工作性的降低导致孔隙水含量较低，而GP和FA的掺入则因工作性的改善而提高了孔隙水含量。孔隙面积与孔隙水有关，而孔隙水又与工作性的改善直接相关。按照SF > MK > GP > FA的顺序，含SF和MK的混合料强度最高，而对于GP和FA，强度随着替代水平的增加和工作性的改善而逐渐降低。在配制低碳水泥的三元和四元胶凝体系时，SF、GP和FA可被视为性能增强剂。
