By using XRD, isothermal microcalorimetry, ESEM, EDS, NMR, the effects silica fume and polycarboxylate superplasticizer (PC) on the hydration behavior of tricalcium silicate (C3S) paste were researched. The results show that: PC suppresses the hydration of C3S while silica fume promotes the hydration of C3S by consumption of generated Ca(OH)2. Both PC and silica fume change the morphology of hydration products C-S-H gel from needle-bar-like to reunion-like, along with the polymerization state of silicon-oxygen tetrahedron varied greatly. Especially silica fume significantly affects Q1, Q2 percentage of silicon-oxygen tetrahedron.

A kind of laminated composite named Al2O3/Nylon/Al with high work of fracture was prepared by a simple process using epoxy resin adhesives as binder in a leaky mold at a pressure of 5 MPa. Light microscopy and scanning electron microscopy were employed to observe the microstructures and crack propagation of the laminated composites. The flexural strength and fracture toughness were measured through three-point bending test, and the work of fracture of the laminated composite was calculated from load-displacement curves of three-point bending test. The experimental results show the composite have low Young's modulus and flexural strength, however, the work of fracture of the laminated composite appears to be high of 2850 J/m2, and the fracture toughness reaches about 11 MPa•m1/2. Analysis of microstructure and crack propagation reveals that the failure of the laminated composite exhibit distinctive characteristic.

Industrial wastewater sludge contains a certain amount of heavy metals, which will cause environmental pollution. In this paper high Cr, Zn content wastewater sludge from steel plant was used as the main raw material, with Kaolin and other materials as adjustment materials. Through optimization design of raw mix composition and firing system, a kind of function aggregate was got, which had an apparent relative density of about 3.0 g/cm3, a vacuum water absorption between 16%~23%, and a linear attenuation coefficient more than 0.15cm-1. Use XRD and SEM to analyze the existence state of heavy metals in aggregates. The novel method for making function aggregates provides a technical support for resource utilization of steel wastewater sludge, which could be applied in the field of high strength concrete and radiation shielding concrete.

In this article, through the measurements on neat cement paste strength and heat of hydration at the early stage and using several analytical methods including XRD and SEM, effect of large amount of fly ash on the hydration process and cement's hardening mechanism of portland cement was studied when water to binder ratio is 0.35 and fly ash content is between 20% and 50%.The research outcomes find that the pozzolanic activities of fly ash are not good at the early stage.The more the content of fly ash was, the bigger the effect on strength would be.

In this study complex cementitious systems were prepared by cement, slag, fly ash and silica fume. Changing the dosages of mineral admixtures, then studying the strength and micro-structure of harden cement pastes by XRD,SEM,BET etc. Comparing the influence of variety and dosage of mineral admixture on cement pastes.Finally we found that mineral admixtures could improve the pore size distribution of cement pastes, and the total dosage 10% is better than 20%; and the "FA+SF" is better than others.