Khan Muhammad I, Usman Muhammad, Rizwan Syed A, Hanif Asad
School of Civil and Environmental Engineering, National University of Science and Technology (NUST), Sector H-12, Islamabad, Pakistan.
National University of Computer & Emerging Sciences (NUCES-FAST), Faisal town, Lahore, Pakistan.
Materials (Basel). 2019 Sep 19;12(18):3050. doi: 10.3390/ma12183050.
This paper assesses the mechanical and structural behavior of self-consolidating lightweight concrete (SCLWC) incorporating bloated shale aggregate (BSA). BSA was manufactured by expanding shale pellets of varying sizes by heating them up to a temperature of 1200 °C using natural gas as fuel in the rotary kiln. Fly ash (FA) and limestone powder (LSP) were used as supplementary cementing materials (10% replacement of cement, each for LSP and FA) for improved properties of the resulting concrete. The main parameters studied in this experimental study were compressive strength, elastic modulus, and microstructure. The fresh-state properties (Slump flow, V-funnel, J-Ring, and L-box) showed adequate rheological behavior of SCLWC in comparison with self-consolidating normal weight concrete (SCNWC). There was meager (2-4%) compressive strength reduction of SCLWC. Lightweight aggregate tended to shift concrete behavior from ductile to brittle, causing reduced strain capacity and flexural toughness. FA and LSP addition significantly improved the strength and microstructure at all ages. The study is encouraging for the structural use of lightweight concrete, which could reduce the overall construction cost.
本文评估了掺入膨胀页岩骨料（BSA）的自密实轻质混凝土（SCLWC）的力学和结构性能。BSA是通过在回转窑中使用天然气作为燃料将不同尺寸的页岩颗粒加热至1200°C进行膨胀制造而成。粉煤灰（FA）和石灰石粉（LSP）用作辅助胶凝材料（LSP和FA各替代10%的水泥），以改善所得混凝土的性能。本试验研究中所研究的主要参数为抗压强度、弹性模量和微观结构。与自密实普通重量混凝土（SCNWC）相比，新拌状态性能（坍落扩展度、V型漏斗试验、J环试验和L型箱试验）表明SCLWC具有足够的流变性能。SCLWC的抗压强度有轻微降低（2 - 4%）。轻质骨料倾向于使混凝土行为从延性转变为脆性，导致应变能力和弯曲韧性降低。添加FA和LSP显著提高了各龄期的强度和微观结构。该研究对于轻质混凝土的结构应用具有鼓舞作用，这可能会降低总体施工成本。
