Carabba Lorenza, Manzi Stefania, Bignozzi Maria Chiara
Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, via Terracini, 28, Bologna 40131, Italy.
Materials (Basel). 2016 Jul 18;9(7):586. doi: 10.3390/ma9070586.
Present concerns about global warming due to the greenhouse emissions in the atmosphere have pushed the cement industry to research alternatives to ordinary Portland cement (OPC). Geopolymer binder may constitute a possible breakthrough in the development of sustainable materials: understanding the effectiveness and the influences of superplasticizers on geopolymer systems is one of the essential requirements for its large-scale implementation. This study aims to investigate the possibility of using commercially available chemical admixtures designed for OPC concrete, to improve fresh properties of fly ash-based geopolymers and mortars. A special emphasis is laid upon evaluating their influence on mechanical and microstructural characteristics of the hardened material realized under room-temperature curing conditions. Results indicate that the addition of a polycarboxylic ether-based superplasticizer, in the amount of 1.0 wt. % by mass of fly ash, promotes an improvement in workability without compromising the final strength of the hardened material. Moreover, the addition of the polycarboxylic ether- and acrylic-based superplasticizers induces a refinement in the pore structure of hardened mortar leading to a longer water saturation time.
目前，由于大气中温室气体排放引发的全球变暖问题，促使水泥行业研究普通硅酸盐水泥（OPC）的替代品。地质聚合物粘结剂可能是可持续材料发展中的一个突破：了解高效减水剂对地质聚合物体系的有效性和影响是其大规模应用的基本要求之一。本研究旨在探讨使用为OPC混凝土设计的市售化学外加剂来改善粉煤灰基地质聚合物和砂浆新拌性能的可能性。特别强调评估它们对室温养护条件下硬化材料的力学和微观结构特征的影响。结果表明，添加占粉煤灰质量1.0 wt.% 的聚羧酸醚基高效减水剂，可提高工作性，且不影响硬化材料的最终强度。此外，添加聚羧酸醚基和丙烯酸基高效减水剂会使硬化砂浆的孔结构细化，导致饱水时间延长。
