Pundienė Ina, Pranckevičienė Jolanta, Kligys Modestas, Girskas Giedrius
Laboratory of Concrete Technology, Institute of Building Materials, Vilnius Gediminas Technical University, Linkmenų Str. 28, LT-08217 Vilnius, Lithuania.
Materials (Basel). 2022 Apr 17;15(8):2925. doi: 10.3390/ma15082925.
As the construction of hydrotechnical and energy facilities grows worldwide, so does the need for special heavyweight concrete. This study presents the analysis of the influence of waste-metal particle filler (WMP) on Portland cement (PC) paste and mortars with pozzolanic (microsilica and metakaolin) additives in terms of the hydration process, structure development, and physical-mechanical properties during 28 days of hardening. Results have shown that waste-metal particle fillers prolong the course of PC hydration. The addition of pozzolanic additives by 37% increased the total heat value and the ultrasound propagation velocity (UPV) in WMP-containing paste by 16%; however, in the paste with only WMP, the UPV is 4% lower than in the WMP-free paste. The density of waste-metal particle fillers in the free mortar was about two times lower than waste-metal particle fillers containing mortar. Due to the lower water absorption, the compressive strength of WMP-free mortar after 28 days of hardening achieved 42.1 MPa, which is about 14% higher than in mortar with waste-metal particle filler. The addition of pozzolanic additives decreased water absorption and increased the compressive strength of waste-metal particle filler containing mortar by 22%, compared to pozzolanic additive-free waste-metal particle fillers containing mortar. The pozzolanic additives facilitated a less porous matrix and improved the contact zone between the cement matrix and waste-metal particle fillers. The results of the study showed that pozzolanic additives can solve difficulties in local waste-metal particle fillers application in heavyweight concrete. The successful development of heavyweight concrete with waste-metal particle fillers and pozzolanic additives can significantly expand the possibility of creating special concrete using different local waste. The heavyweight concrete developed by using waste-metal particle fillers is suitable for being used in load balancing and in hydrotechnical foundations.
随着全球水工和能源设施建设的增加，对特殊重质混凝土的需求也在增长。本研究分析了废金属颗粒填料（WMP）对含有火山灰质（微硅粉和偏高岭土）添加剂的波特兰水泥（PC）浆体和砂浆在水化过程、结构发展以及硬化28天期间物理力学性能的影响。结果表明，废金属颗粒填料会延长PC的水化过程。添加37%的火山灰质添加剂可使含WMP浆体的总热值和超声传播速度（UPV）提高16%；然而，仅含WMP的浆体中，UPV比不含WMP的浆体低4%。自由砂浆中废金属颗粒填料的密度比含废金属颗粒填料的砂浆低约两倍。由于吸水率较低，不含WMP的砂浆在硬化28天后的抗压强度达到42.1MPa，比含废金属颗粒填料的砂浆高约14%。与不含火山灰质添加剂的含废金属颗粒填料的砂浆相比，添加火山灰质添加剂可降低吸水率，并使含废金属颗粒填料的砂浆抗压强度提高22%。火山灰质添加剂促进形成孔隙较少的基体，并改善了水泥基体与废金属颗粒填料之间的接触区。研究结果表明，火山灰质添加剂可以解决在重质混凝土中局部应用废金属颗粒填料的难题。成功开发含废金属颗粒填料和火山灰质添加剂的重质混凝土可以显著扩大利用不同当地废料制备特殊混凝土的可能性。利用废金属颗粒填料开发的重质混凝土适用于负载平衡和水工基础。
