Research on the development of lightweight concrete (LWC) utilizing wastes and natural resources as lightweight aggregates (LWA) is increasingly gaining attention worldwide due to sustainable and environmental concerns. A new alternative is using palm kernel oil polyol (PKO-p)-based polyurethane (PU) as filler. Rigid PU is a block copolymer comprised of a monomeric PKO-p and 2, 4-methylene diphenyl diisocyanate (crude MDI). The property of PKO-p, its ratio with crude MDI and reaction time were determined. The reaction time showed the average of 60 s for cream time and 95 s for rise time with maximum hardening time of 8 min. The reaction between PKO-p to MDI at 1:1 ratio resulted in a very short hardening time (within 2 min). The compressive strength of the rigid PU was at 7.0 MPa at a density of 206 kg/m3. Further increase in the amount of PKO-p increased the density and compressive strength of the PU. PU aggregate in the concrete mixture was added at 1 to 5% (w/w) to obtain concrete with density of less than 1800 kg/m3. The resulting concrete has excellent compressive strength (17.5 MPa) and thermal conductivity (0.24 W/m⋅K). The results showed that physical properties of PU played the most significant effect on the physical and mechanical properties of the lightweight concrete.
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机译:由于可持续性和环境问题,利用废物和自然资源作为轻质骨料(LWA)开发轻质混凝土(LWC)的研究越来越受到全世界的关注。一种新的替代方法是使用基于棕榈仁油多元醇(PKO-p)的聚氨酯(PU)作为填料。刚性PU是由单体PKO-p和2,4-亚甲基二苯基二异氰酸酯(粗MDI)组成的嵌段共聚物。测定了PKO-p的性质,其与粗MDI的比例和反应时间。反应时间显示出乳霜时间平均为60 s,上升时间平均为95 s,最大硬化时间为8分钟。 PKO-p与MDI的比例为1:1的反应导致非常短的硬化时间(2分钟内)。刚性PU的抗压强度为7.0MPa,密度为206kg / m 3。 PKO-p量的进一步增加增加了PU的密度和抗压强度。将混凝土混合物中的PU集料以1至5%(w / w)的量添加,以获得密度小于1800 kg / m3的混凝土。所得混凝土具有优异的抗压强度(17.5 MPa)和导热系数(0.24 W / m·K)。结果表明,PU的物理性能对轻质混凝土的物理和机械性能影响最大。
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