Sharaky Ibrahim A, Elamary Ahmed S, Alharthi Yasir M
Civil Engineering Department, College of Engineering, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
Materials (Basel). 2022 Jun 21;15(13):4385. doi: 10.3390/ma15134385.
In this paper, the recycled fine aggregates and powders produced from crushing old basaltic concrete and natural basalt were used to produce new concrete. The sand was partially replaced by two types of recycled wastes at five percentages: 0%, 20%, 40%, 60%, and 80%. The cement was partially replaced by recycled powders and silica fume (SF) at four percentages: 0, 5%, 10%, and 20%. The concrete strengths and water absorption were obtained at several curing ages. The obtained results emphasized the positive effects of increasing the curing time on enhancing the concrete properties, regardless of the types or the waste sources. Moreover, the recycled powders retarded the hydration reaction. In addition, the recycled fine aggregates and powders could achieve about 99.5% and 99.3% of the ordinary concrete strength and enhance the tensile strength. Furthermore, the mix containing 40% of recycled fine concrete aggregate diffused the highest contents of both calcium and silicate, which led to enhancing the interfacial transition zone (ITZ) and concrete properties, compared to the other tested mixes. Finally, the water absorption of all tested concrete mixes decreased with an increase in the curing age, while the mixes integrating 10% and 20% of SF experienced the lowest values of water absorption.
在本文中，由破碎废旧玄武岩混凝土和天然玄武岩产生的再生细骨料和粉末被用于制备新混凝土。砂被两种类型的再生废料以0%、20%、40%、60%和80%这五个比例部分替代。水泥被再生粉末和硅灰（SF）以0、5%、10%和20%这四个比例部分替代。在几个养护龄期测定了混凝土强度和吸水率。所得结果强调了增加养护时间对改善混凝土性能的积极影响，无论废料类型或来源如何。此外，再生粉末延缓了水化反应。另外，再生细骨料和粉末可达到普通混凝土强度的约99.5%和99.3%，并提高抗拉强度。此外，与其他测试混合料相比，含有40%再生细混凝土骨料的混合料扩散出的钙和硅酸盐含量最高，这导致界面过渡区（ITZ）和混凝土性能得到改善。最后，所有测试混凝土混合料的吸水率随养护龄期的增加而降低，而掺入10%和20%硅灰的混合料吸水率最低。
