The microstructures of fine recycled concrete aggregate (FRCA) after modifications in cement mortar were studied. The result indicated that the modification of RFA could strengthen the enhancement effect on microstructure when modified by 20wt% silica fume (SF) grout, 10wt% Polyvinyl alcohol (PVA) solution. After modification by SF grout and PVA solution, the thickness of interfacial transition zone (ITZ) of RFA cement mortar was decreased by 50% compared with the unmodified samples. The ITZ between RFA and cement paste was studied and the surface microstructure and sectional morphology of RFA was observed by scanning electron microscopy (SEM). Analyzing the modification mechanism and Building the superficial micro-structure model of RFA in cement mortar was carried out.

Water and bottom sediment samples were taken from the Zhenjiang section of the lower reach of Yangtze River, China during the autumn of 2011, aimed to study the pollution levels of six kinds of phthalate acid esters (PAEs). Water samples were prepared by solid-phase extraction (SPE) and analyzed by gas chromatography-mass spectrometry (GC–MS), with spiked recoveries ranging from 33.5% to 121.0%. Sediment samples were pretreated using ultrasonic-assisted organic solvent extraction, with recoveries varying from 43.7% to 107.6%. Results showed that the concentration levels of PAEs are below the limit of detection (LOD) –63.3μg/L in the water samples of Yangtze River. Tongji River water are severely contaminated by PAEs, with the concentrations of di-n-butyl phthalate (DnBP) up to 613ug/L. Four of PAEs were detected in the tap water of Zhenjiang. It was also found that all of detected PAEs are dominantly partitioned on suspended solids in water samples. The concentrations of PAEs in sediment samples are ranged from <LOD to 7.5mg/kg.

The effect of admixtures on the mechanical properties of recycled fine aggregate cement mortar was studied. The result indicated that compared with blank samples the 28d flexural strength, the compressive strength and osmotic pressure of cement mortar were increased by 15.6%, 35.5%, 41.1% respectively when adding silicone waterproofing agent 0.2wt%, naphdalin series water reducer 1.0wt%, polycarboxylate superplasticizer 0.8wt%. The micro-morphology and hydration products of mortar specimens was observed by SEM, XRD respectively.

The effect of some factors(dosage and grain size of recycled fine aggregate of construction waste, content of mineral admixture) on the properties of cement mortar was studied. The results indicated that when recycled fine aggregate particles gradation was areaⅡ, replacement percentage (sand) was 60%,dosage of mineral admixture was 36%, compared with blank sample, the 28d flexural strength and the compressive strength of cement mortar samples were increased by 30.7% and 37.2%, respectively. Micro-morphology of section on cement mortar was observed by SEM. Identifying the hydration products through XRD was carried out.

The influence of the naphthalene superplasticizer, aliphatic superplasticizer and water repellent on the properties of sulphoaluminate cement mortar such as strength and anti permeability was studied by orthogonal test method, and the microstructure of hydration products of hardened mortar was observed by X-Ray and SEM. The results showed that, adding amount of additive in sulphoaluminate cement, can improve mechanical properties of sulphoaluminate cement, and effectively improve waterproof performance and impermeability of mortar. When the water repellent admixture is 0.2%, the naphthalene superplasticizer 0.7%, aliphatic superplasticizer 1%, mortar impermeability is at its best, reaching 1.6MPa.