Haustein Elżbieta, Kuryłowicz-Cudowska Aleksandra, Łuczkiewicz Aneta, Fudala-Książek Sylwia, Cieślik Bartłomiej Michał
Department of Mechanics of Materials and Structures, Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland.
Department of Water and Wastewater Technology, Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland.
Materials (Basel). 2022 Feb 18;15(4):1547. doi: 10.3390/ma15041547.
The amount of fly ash from the incineration of sewage sludge is increasing all over the world, and its utilization is becoming a serious environmental problem. In the study, a type of sewage sludge ash (SSA) collected directly from the municipal sewage treatment plant was used. Five levels of cement replacement (2.5%, 5%, 7.5%, 10% and 20%) and unchanged water-to-binder (w/b) ratio (0.55) were used. The purpose of the study was to evaluate the effect of sewage sludge ash (SSA) on the hydration heat process of cement mortars. The heat of the hydration of cement mortars was monitored by the isothermal calorimetric method for 7 days at 23 °C. The analysis of chemical composition and particle size distribution was performed on the tested material. The tests carried out have shown that SSA particles have irregular grain morphology and, taking into account the chemical composition consists mainly of oxides such as CaO, PO, SiO and AlO. The concentration of these compounds affects the hydration process of cement mortars doped with SSA. In turn, the content of selected heavy metals in the tested ash should not pose a threat to the environment. Calorimetric studies proved that the hydration process is influenced by the presence of SSA in cement mortars. The studies showed that the rate of heat generation decreased (especially in the initial setting period) with the increasing replacement of cement by SSA, which also reduced the amount of total heat compared to the control cement mortar. With increasing mass of the replacement of cement with SSA up to 20%, the 7-day compressive strength of the mortar samples decreases.
全球范围内，污水污泥焚烧产生的飞灰量不断增加，其利用正成为一个严峻的环境问题。在本研究中，使用了直接从城市污水处理厂收集的一种污水污泥灰（SSA）。采用了五个水泥替代水平（2.5%、5%、7.5%、10%和20%）且水胶比（w/b）保持不变（0.55）。本研究的目的是评估污水污泥灰（SSA）对水泥砂浆水化热过程的影响。在23℃下，采用等温量热法监测水泥砂浆7天的水化热。对测试材料进行了化学成分分析和粒度分布分析。所进行的测试表明，SSA颗粒具有不规则的颗粒形态，考虑其化学成分主要由CaO、PO、SiO和AlO等氧化物组成。这些化合物的浓度会影响掺有SSA的水泥砂浆的水化过程。反过来，测试灰中选定重金属的含量对环境不应构成威胁。量热研究证明，水泥砂浆中SSA的存在会影响水化过程。研究表明，随着SSA替代水泥量的增加，产热速率降低（尤其是在初凝期），与对照水泥砂浆相比，总热量也有所减少。随着SSA替代水泥的质量增加至20%，砂浆样品的7天抗压强度降低。
