广钢电炉粉尘分析及治理利用探讨

对广州钢铁厂含铅锌电炉粉尘进行了分析测定，提出将电炉粉尘用作水泥生产铁质校正料的设想，并进行了可行性试验。     

一种高性能水泥生产配料自动控制系统的设计与实现

利用STD总线工控机构成水泥生产配料自动控制系统,不但提高了配料精度,而且系统自动化程度高、操作使用方便、抗干扰能力强,提高了产品的质量和生产效率．     

Crack Growth Resistance of Hybrid Fiber-Reinforced Cement Matrix Composites

The effect of hybrid fiber reinforcement on fracture energy and crack propagation in cement matrix composites is examined. The crack in cement matrix composites is allowed to fracture under mode-I loading with three-point bending beam specimens. The influence of fiber types and their combination is quantified by using the toughness index and fracture energy. A proper hybrid combination of steel fibers and polyvinyl alcohol microfibers enhances the resistance to both the nucleation and growth of the crack. The micromechanical model of hybrid composites by using a fiber bridging law is emphasized, and the numerical model prediction closely matches the behavior obtained from the experiment. The influencing role of the material parameters in the fracture tests (e.g., the fracture toughness index and fracture energy) becomes more apparent than ones used in some conventional strength-based or fiber pullout tests, and these fracture parameters could screen the effect of fiber/microfiber reinforcement in enhancing the crack growth resistance of cementitious composites. This study demonstrates that fundamental fracture tests are effective to characterize and develop high-performance hybrid fiber–reinforced cement matrix composites.     

Effect of compressive stress on the ferroelectric hysteresis behavior in 0-3 PZT-cement composites

Lead zirconate titanate (PZT)-cement composites of 0-3 connectivity were produced using 50% PZT vol. content. PZT-cement based composites are developed for use as sensors for smart concrete structures, however, these sensors would in real life be under a certain stress. The effect of stress on the ferroelectric polarization-electric field (P-E) hysteresis of the composites is reported in this present work. It was found that there was a small but noticeable reduction in the remnant polarization (P_ir) by ≈ 0.3-0.7 μC/cm² while the coercive field (E_ic) remained approximately the same when the stress was increased from 0 to 57 MPa.     

水泥砂浆抗腐蚀性能试验研究

从质量损失率的角度研究了聚合物与火山灰在不同掺量下对水泥砂浆抗腐蚀性能的影响,并得出了抗腐蚀性能最佳时的聚合物与火山灰掺量。试验结果表明,在水泥砂浆中同时掺入聚合物和火山灰能明显提高其密实性,增强其抗腐蚀性能。通过对比,抗腐蚀性能最佳时的配比为:聚合物取水泥用量的25%,火山灰取水泥用量的20%。     

G60S防窜剂在板深78-1井长封固段固井中的应用

大港油田板深78-1井是一口定向深探井,完钻井深4560m,套管下深4554.04m,井底静止温度为142℃,循环温度为115℃。固井水泥采用嘉华G级加35％硅粉,外加剂用G60S防窜剂和H88高温缓凝剂,固井采用双胶塞,固井时水泥浆平均密度为1.83g/cm~3。经CBL测井结果表明,水泥浆从井底返至井深2293m,封固段长2261m,全井封固优质段累计达1693m,优质率达74.9％。固井效果良好。     

一种评价水泥浆沉降稳定性的新方法——微压力波动测试水泥浆滤失—沉降耦合作用

目前的水泥浆沉降稳定性测试方法缺乏对沉降过程的描述。为了提高水泥浆沉降稳定性测试的准确性与科学性,设计了一种微压力波动测试仪,对滤失—沉降耦合作用的水泥浆柱分段压力波动进行测试,据此评价浆体的上、下密度差,并对不同黏度、温度、降失水剂、固相颗粒和触变性的水泥浆稳定性进行了分析。研究结果表明:①水泥浆沉降过程可分为高速期、低速期、稳定期和失重期,高速期滤失可减小浆体的上、下密度差;②滤失量越大、黏度越低、同类材料水固比越大,密度差越大、沉降稳定性越差;③温度对沉降稳定性的影响因降失水剂的协同作用而呈现出无规律性,高分子聚合物类降失水剂效果强于成膜类;④提高水泥浆触变性可改善浆体的沉降分层现象,胶凝强度的形成时间越短,效果越好。结论认为,较之于常规方法,该评价水泥浆沉降稳定性的新方法,可以对沉降全过程进行描述,并考虑了滤失对沉降的影响,更加贴合于井下的实际情况。     

浅谈岩土预应力锚索孔道水泥灌浆的质量控制

岩土预应力锚固技术遍及土木工程的各个领域,如边坡、坝体、桥梁等。而岩土预应力锚索周围介质多为岩体和土体,环境条件比较复杂,高拉应力作用下的锚索腐蚀断裂,是威胁预锚使用寿命的主要因素。本文结合拉力型粘结式预应力锚索浅析岩土预锚从施工准备、成孔、锚索制作与安装、孔道灌浆的全过程对孔道水泥灌浆的影响因素和各环节质量控制,以确保孔道水泥灌浆的质量,为锚索提供可靠的锚固力和防腐蚀保障。     

添加EVA对水泥砂浆水化过程的影响

本文采用偏光显微镜、X射线衍射、综合热分析、红外光谱、扫描电镜等手段研究了添加EVA对水泥砂浆水化过程的影响。实验结果表明,聚合物的加入对各龄期水泥水化进程会有一定的抑制作用。     

Role of cement content on the properties of self-flowing Al2O3 refractory castables

In this work, Al₂O₃ self-flowing castables (SFCs) were produced based on various cement contents. The SFCs were sintered at 1273 K, 1573 K and 1773 K and the exhibited properties were experimentally determined. Among the properties determined in this work are bulk density (BD), apparent porosity (AP), water absorption (WA), cold crushing strength (CCS), modulus of rupture (MOR) and fracture toughness (K_IC). It is found that additions of 5% cement lead to SFCs with maximum MOR and K_IC values after firing at 1773 K. Firing at 1573 K leads to a reduction in both, MOR and K_IC. In SFC containing 3% cement, maximum K_IC values of 3.53 MPa m^1/2 were achieved after firing at 1573 K. In the low cement SFCs (1 wt%) after firing at 1773 K the exhibited K_IC values were below those obtained in either the SFC-3 or SFC-5, but they were significantly high (3.43 MPa m^1/2).