混凝土预拌厂废浆水均化技术研究

通过合成一种新型的丙烯酸-丙烯酸羟丁酯-磺酸盐均化剂,对混凝土预拌厂废浆水进行了均化处理,并对均化后混凝土预拌厂废浆水的物理性能、使用均化后废浆水的混凝土性能进行了系统研究。结果表明,该均化剂可显著降低混凝土预拌厂废浆水的黏度,经处理后的预拌厂废浆水可100%替代清水使用,且对混凝土的工作性能、力学性能无不利影响。

Abrasion Resistance of Cement Paste with Granulated Blast Furnace Slag and Its Relations to Microhardness and Microstructure

The abrasion resistance of cement pastes with 30 wt%,40 wt%and 50 wt%granulated blast furnace slag(GBFS),and its relations to microhardness and microstructure like hydration products and pore structure were studied.Results indicated that GBFS decreased the abrasion resistance of paste,and among the pastes with GBFS,the paste with 40 wt%GBFS showed the highest abrasion resistance.The microhardness of GBFS was lower than that of the cement,and the microhardness of the hydration products in paste with GBFS was also lower than that of the hydration products in paste without GBFS,so that the abrasion resistance of paste decreased when GBFS was incorporated.The reason for the decrease of microhardness of pastes with GBFS was that the contents of Ca(OH)_(2)in pastes with GBFS was significantly lower than that in the paste without GBFS,while large amounts of calcium aluminate hydrates and hydrotalcite-like phases(HT)in pastes with GBFS were generated.Furthermore,among the pastes with GBFS,the paste with 40 wt%GBFS showed the lowest porosity which was the main reason for its highest abrasion resistance.

不同强度陶砂海工混凝土的配制

通过正交试验,研究了水灰比、陶砂、粉煤灰、矿粉对混凝土28 d标养抗压强度、28 d海水干湿循环抗压强度、28 d标养试件电通量、28 d海水干湿循环养护试件电通量的影响。结果表明,随水灰比的降低,混凝土强度提高,抗氯离子渗透性逐渐提高;随粉煤灰、陶砂掺量的增加,混凝土强度逐渐降低,抗氯离子渗透性能先增强后降低;随矿粉掺量的增加,强度几乎无变化,但抗氯离子渗透性能逐渐增强。经JMP软件预测刻画器分析,分别得到C40、C50、C60最优配比,试验验证表明,该最优配比与理论值接近,符合强度和耐久性要求。

钢渣作胶凝材料和细集料制备高性能砂浆的研究

本文通过测试钢渣粉的活性、安定性和钢渣砂的颗粒级配、含水率、含泥量、吸水率、安定性等基本性能,研究陈化龄期对钢渣砂安定性的影响。利用安定性合格、级配合理的钢渣砂、钢渣粉、矿渣粉、激发剂和工作性能、凝结时间调节组分,通过配合比设计制备出工作性能良好、凝结时间合理、力学性能优良的高性能砂浆,并对其体积稳定性能进行研究。

再生微粉对海工混凝土抗氯离子侵蚀性能影响的研究

混凝土预拌厂废渣与其它废渣粉磨制备再生微粉,采用RCM法研究再生微粉对混凝土氯离子扩散系数的影响规律,同时制备相应水泥净浆,通过XRD、SEM、MIP、EDS等测试方法分析其作用机理。结果表明,再生微粉可显著减小海工混凝土氯离子扩散系数。再生微粉减少了水化产物中Ca(OH)2含量,生成了低钙硅比的C-S-H凝胶,同时优化了孔结构,提高了海工混凝土的抗氯盐侵蚀性能。

基于体积损失速率的混凝土抗冲磨性能评价

采用风砂枪法并配合图像分析技术,揭示了两组不同混凝土质量损失速率、体积损失速率、被磨损物料的密度、固定纵断面上冲坑轮廓随时间的变化规律,结合各特征时间节点处混凝土的表观形貌,确定了混凝土冲磨破坏稳定阶段的判据,并结合混凝土抗冲磨强度计算结果优选出了可靠的抗冲磨强度评价指标。结果表明:质量损失速率和体积损失速率在某个时间点处同时趋于稳定,此时,被磨损物料的密度与混凝土的表观密度保持一致,且无论从混凝土表面形态还是冲坑轮廓来看,混凝土均表现出稳定且均匀的磨损,由此可以判断该阶段为混凝土冲磨破坏稳定阶段。研究证明,趋于稳定的体积损失速率才是混凝土抗冲磨强度可靠的评价指标。