Poudel Sandip, Menda Samrawit, Useldinger-Hoefs Joe, Guteta Lidya E, Dockter Bruce, Gedafa Daba S
Red River Valley Alliance LLC, 4816 Amber Valley Pkwy S, Fargo, ND 58102, USA.
Bingham Engineering Consultants, 13416 N. 32nd St. Suite 100, Phoenix, AZ 85032, USA.
Materials (Basel). 2024 May 14;17(10):2316. doi: 10.3390/ma17102316.
Cement production requires considerable energy and natural resources, severely impacting the environment due to harmful gas emissions. Coal bottom ash (CBA) and coal boiler slag (CBS), byproducts of coal-fired powerplants having pozzolanic properties, can be mechanically ground and replace cement in concrete, which reduces waste in landfills, preserves natural resources, and reduces health hazards. This study was performed to determine the optimum cement replacement amount of ground CBA (GCBA) and ground CBS (GCBS) in concrete, which was 10% for GCBA and 5% for GCBS. GCBA-based concrete exhibited superior tensile strength, modulus of elasticity, and durability compared to the control. In the Rapid Chloride Penetration Test, 10% GCBA concrete resulted in 2026 coulombs at 56 days, compared to 3405 coulombs for the control, indicating more resistance to chloride penetration. Incorporating 2.5% nanoclay in GCBA-based concrete increased the optimum GCBA content by 5%, and the compressive strength of 15% GCBA concrete increased by 4 MPa. The mortar consisting of the finest GCBA(L1) having Blaine fineness of 3072 g/cm yielded the highest compressive strength (32.7 MPa). The study discovered that the compressive strength of GCBA and GCBS-based mortars increases with fineness, and meeting the recommended fineness limit in ASTM C618 enhances concrete or mortar properties.
水泥生产需要大量能源和自然资源，由于有害气体排放，对环境造成严重影响。煤底灰（CBA）和煤锅炉炉渣（CBS）是具有火山灰特性的燃煤发电厂的副产品，可以进行机械研磨并替代混凝土中的水泥，这减少了垃圾填埋场的废物，保护了自然资源，并降低了健康危害。本研究旨在确定混凝土中磨细煤底灰（GCBA）和磨细煤锅炉炉渣（GCBS）的最佳水泥替代量，GCBA为10%，GCBS为5%。与对照组相比，基于GCBA的混凝土表现出更高的抗拉强度、弹性模量和耐久性。在快速氯离子渗透试验中，10%GCBA混凝土在56天时的电量为2026库仑，而对照组为3405库仑，表明其对氯离子渗透的抵抗力更强。在基于GCBA的混凝土中掺入2.5%的纳米粘土可使最佳GCBA含量提高5%，15%GCBA混凝土的抗压强度提高4MPa。由勃氏比表面积为3072g/cm的最细GCBA（L1）组成的砂浆具有最高的抗压强度（32.7MPa）。研究发现，基于GCBA和GCBS的砂浆的抗压强度随细度增加而提高，满足ASTM C618中推荐的细度限值可提高混凝土或砂浆的性能。
