Kharel Sahul, Yu Hua, Lau Chooi Kim, Ng Kam
Department of Civil and Architectural Engineering and Construction Management, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071, United States of America.
Department of Civil and Architectural Engineering and Construction Management, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071, United States of America.
Sci Total Environ. 2024 Dec 1;954:176472. doi: 10.1016/j.scitotenv.2024.176472. Epub 2024 Sep 23.
Coal char is a coal-derived product produced by pyrolysis of char, which has valuable applications in the production of building materials. This paper presents the use of coal char in developing coal char-based cement mortar. Coal char is used to replace the sand, partially, at different proportions in cement mortar, and the change in properties is studied. Four cement types are used in the initial study, and one is selected for a detailed study based on the water retention, density, and compressive strength of the mortar. The properties of coal char-based mortar for the selected cement are comprehensively evaluated in terms of flow, water retention, air content, density, compressive strength, flexural strength, porosity, water absorption, drying shrinkage, thermal conductivity, thermogravimetric and differential thermal analysis, and scanning electron microscopy. The addition of coal char at an optimum sand replacement content of 5 % increases the compressive strength of mortar by 17.55 % and the flexural strength by 17.57 %, compared to conventional cement mortar. The thermal conductivity reduces by a maximum of 20 %, compared to traditional cement mortar. This paper also presents a study to compare the addition of coal char and commercial biochar on the properties of masonry cement mortar. The compressive strength of mortar with coal char is 44.39 % greater than that of mortar with the same content of biochar. The addition of coal char as a new sand replacement material shows good potential in improving the engineering properties of mortar.
煤焦是一种通过煤热解产生的煤衍生产品，在建筑材料生产中具有重要应用。本文介绍了煤焦在开发煤焦基水泥砂浆中的应用。在水泥砂浆中，煤焦被用于以不同比例部分替代沙子，并研究其性能变化。初步研究使用了四种水泥类型，基于砂浆的保水性、密度和抗压强度选择了一种进行详细研究。对所选水泥的煤焦基砂浆的性能，从流动度、保水性、含气量、密度、抗压强度、抗折强度、孔隙率、吸水率、干燥收缩、热导率、热重和差热分析以及扫描电子显微镜等方面进行了综合评估。与传统水泥砂浆相比，在最佳沙子替代量为5%时添加煤焦，可使砂浆的抗压强度提高17.55%，抗折强度提高17.57%。与传统水泥砂浆相比，热导率最大可降低20%。本文还进行了一项研究，比较添加煤焦和商业生物炭对砌筑水泥砂浆性能的影响。含煤焦的砂浆的抗压强度比含相同含量生物炭的砂浆高44.39%。添加煤焦作为一种新型沙子替代材料，在改善砂浆工程性能方面具有良好潜力。
