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ABSTRACT
Kenaf fiber (KF) has been applied in concrete to compensate for the weak tensile strength. Similarly, recycled concrete aggregate (RCA) is applied to reduce problems associated with waste concrete materials. However, both KF and RCA reduce the compressive strength (fck) of concrete. This study involves addition of calcite-producing bacillus subtilis bacteria to recycled aggregate concrete (RAC) incorporated with KF. The bacteria is added to concrete with varying proportions of RCA and KF to produce bio-fibrous recycled concrete (BFRC). The proportions of RCA are 0%, 25% 50% and 75% replacement of coarse aggregate, while KF are 0.2%, 0.5% and 1% of concrete. W/C of 0.45, 0.5, and 0.6 are applied to evaluate the effects of different w/c ratios. The properties evaluated are the fck and the flexural strength (ft) of the concrete samples at 28 days. The results showed that 0.2% KF in bio-concrete (BC) increases the fck by 12%; however, increasing above 0.2% decreases fck. KF in BC increases ft by 60%. Furthermore, 0.5% KF content resulted in highest ft of BRC. Increasing RCA content in bio-recycled concrete and BFRC decreases fck by 30% and 33%, respectively, as well as ft by 13% and 18%, respectively.
摘要
红麻纤维（KF）已成功地应用于混凝土中，以补偿较弱的抗拉和抗弯强度。同样，再生混凝土骨料（RCA）也被应用于减少与废弃混凝土材料处理相关的问题. 然而，KF和RCA都与混凝土理想抗压强度的降低有关. 本研究涉及在掺有KF的再生骨料混凝土（RAC）中添加产生方解石的枯草芽孢杆菌，以减轻抗压强度损失. 将枯草芽孢杆菌以不同比例的RCA和KF加入混凝土中，生产生物纤维再生混凝土（BFRC）. RCA的比例分别为天然粗骨料的0%、25%、50%和75%，而KF含量分别为混凝土的0.2%、0.5%和1%. 本研究采用0.45、0.5和0.6的水灰比来评估不同水灰比的影响. 评估的力学性能是混凝土样品在28天时的抗压强度（fck）和弯曲强度（ft）. 结果表明，生物混凝土（BC）中0.2%的KF可使fck增加12%，但增加0.2%以上会使fck降低. 在BC样品中加入KF可使ft增加60%. 此外，结果显示0.5%的KF含量导致BRC的最高ft. 此外，增加生物再生混凝土（BRC）和生物纤维再生混凝土（BFRC）中RCA的含量，fck分别降低30%和33%，ft分别降低13%和18%. 这些类型的混凝土适用于具有高弯曲和拉伸应力的结构构件的施工.
Disclosure statement
No potential conflict of interest was reported by the author(s).