Effects of light crude oil contamination on the physical and mechanical properties of geopolymer cement mortar

Fly ash and oil contaminated sand are considered as the two waste materials that may affect environment. This paper investigated the suitability of producing geopolymer cement mortar using oil contaminated sand. A comparison between physical and mechanical properties of mortar produced using geopolymer and Ordinary Portland Cement (OPC), in terms of porosity, hydration and compressive strength, was conducted. The results showed that heat curing can increase the compressive strength of geopolymer mortar up to 54% compared to ambient curing situation. The geopolymer mortar with 1% of light crude oil contamination yielded a 20% higher compressive strength than OPC mortar containing sand with a saturated surface dry condition. Furthermore, the formation of efflorescence decreased as the level of oil contamination decreased. Moreover, the heat curing method increased the kinetic energy and degree of reaction for geopolymer cement mortar, which cause an increment of the density of the pore system and improving the mechanical properties of the resulting composites. From the results of this study, it was demonstrated that geopolymer mortar has the potential of utilizing oil contaminated sand, and reducing its environmental impacts.     

Adsorption efficiency and photocatalytic activity of fly ash-based geopolymer foam mortar

Fly ash-based geopolymer foam mortar (GFM) was used as an adsorbent material to methylene blue (MB) and also the dye removal material using the photocatalytic mechanism. The GFM, containing 50 wt% river sand aggregate, was prepared to have approximately 46% open porosity, pore size distribution between 0.01 and 3.5 mm, and water permeability of 0.2 cm/s. The variation of adsorption efficiency and adsorption capacity with the contact time of the GFM was first evaluated using various GFM dosages (10, 20, 50, 80, and 100 g/L). The adsorption efficiency at equilibrium (AE_e) was found to linearly increase, while adsorption capacity (q_ae) exponentially decayed, with an increase of loading dosages. The photocatalytic removal efficiency of ~100% was obtained with 50, 80, and 100 g/L GFM loading dosages, with a shorter time at higher dosages. The GFM could be reused, without regeneration, for 5 cycles. The AE_e and q_ae for each reused cycle did not noticeably change suggesting the reusability. The photocatalytic removal efficiency, however, was found to decrease with an increase of the reused cycle. After the 5^th cycle, the highest removal efficiency was reduced to ~70%. The attempts to treat the GFMs with hydrochloric (HCl) and phosphoric (H₃PO₄) acid to reduce the excess alkaline did not give satisfactory results as expected. The photocatalytic removal efficiency had subsided after the treatment with both acids.     

水胶比、矿渣掺量对水泥砂浆强度及流动度影响的研究

通过改变矿渣掺量、水胶比试验,研究矿渣水泥砂浆的抗折、抗压强度和流动度变化的规律,找出了矿渣的最优的掺量。     

双柱塞砂浆泵补偿机构的运动分析和仿真

介绍了双柱塞砂浆泵的工作原理，通过对采用摆动滚子从动件的凸轮机构的双柱塞砂浆泵的工作凸轮机构和补偿凸轮机构进行运动学分析，建立了砂浆泵运动机构的仿真模型．用Matlab软件进行了仿真分析，进一步验证了运动学分析模型的正确性．     

丙乳砂浆在庙子头电站溢流面修补上的应用

丙乳砂浆具有优异的粘结性、防渗性和较高的强度，它无毒而且施工工艺简单，用于修补溢流面上的缺陷较为理想，在其它方面的用途也较为广泛。但由于在水工混凝土缺陷处理上应用较晚，可能在众多施工企业中还较陌生，本文将它在庙子头电站溢流面修补上的应用和经验做一些介绍和评价。     

弹性水泥防水砂浆

本文介绍弹性水泥防水砂浆的研制，综合说明弹性体氯丁胶乳和丁苯胶乳水泥防水砂浆的施工工艺。     

利用废弃的泡沫塑料生产保温砌筑砂浆

介绍一种绿色环保砌筑砂浆的生产工艺。通过大量试验 ,测得其保温性和抗压强度均与加气混凝土相近 ,可消除冷桥现象 ,且在工程实践中 ,工作性良好 ,可作为加气混凝土砌筑砂浆 ;因该砂浆大量利用废弃的泡沫塑料 ,对消解白色污染起到积极作用 ,是可以广泛推广的新型建筑材料。     

聚丙烯纤维对水泥砂浆塑性收缩行为的影响

采用自行研制的水泥砂浆塑性收缩应力测试装置和非接触式测长装置,分别研究了低掺量的聚丙烯纤维对水泥砂浆塑性收缩应力和塑性收缩率的影响.结果表明：水泥砂浆的最大塑性收缩力约为28.5 N,最大塑性收缩开裂应力约为0.003 2 MPa;未经改性处理的聚丙烯纤维对水泥砂浆塑性收缩应力影响较小,塑性减裂作用较小,而改性聚丙烯纤维可使其塑性减裂作用明显增加;水泥砂浆的塑性收缩率约为3 600微应变,该数值明显大于水泥基材料硬化后的干燥收缩率;PP纤维对混凝土坍落度及力学性能影响不大,在使用时可主要关注其对水泥基材料的塑性减裂作用.     

聚合砂浆与混凝土粘结劈拉强度的试验研究

进行了砂浆和不同强度混凝土的粘结劈拉试验,试验结果表明,聚合砂浆与混凝土之间的劈拉破坏为粘结面破坏,粘结劈拉强度随混凝土强度的增大而增大。     

PCM聚合物水泥砂浆及混凝土治理渗漏的工艺

结合工程实例，介绍了某小区地下室进行防水、堵漏处理的治理原则，从材料要求、配合比及其性能指标等方面对该工程所需材料进行了论述，分别对墙体施工工艺及地面施工工艺进行了阐述，以推广该技术。