Jia Ying Sun

Study on the Effect of Waste Gypsum on Hardening Paste Structure and Performances of Lime-Fly Ash

Based on the experiments, the effect of waste gypsum on the formation of paste structure, the early strength and the stability of lime-fly ash is discussed in the article. As is shown by the results, the early strength of paste was improved by adding waste gypsum into lime-fly ash. The stability of lime-fly ash paste modified by waste gypsum could meet technical requirements when waste gypsum admixture was less than 40%. With the increase of hydration age, the number of ettringite (AFt) and C-S-H gel in paste would increase.

Research on Performance of Steel Slag and Porous Cement Concrete Made by Steel Slag Aggregate

Porous cement concrete, which has some superiority in environmental protection compared with normal concrete, has been more widely applied. Performance of Steel Slag and influence of the steel slag aggregate on physical and mechanical properties and durability of porous cement concrete were studied in this paper. Based on study of porous cement concrete properties, the paper puts forward several typical pavement structure forms in engineering application of porous cement concrete from finite element analysis method.

Study on Hydration Mechanism of Slag Activated by Alkaline

By measuring the heat of hydration during the hydration of water quenched slag produced by molten iron boiler water, combined with water quenching measurements, infrared spectroscopy, X-ray diffraction, differential thermal analysis and electron microscopy observation and analysis, the authors argued that the type of water quenched slag is a kind of potential activity of the vitreous structure. Protective film theory (the surface layer of silicon-oxygen network) is put forward. Therefore, the slag hydration must be excited in the activator destruction of this layer of film, and this hydration process can be divided into three stages. They are: the early hydration of sodium silicate hardening; slag’s surface structural damage and the network structure dissolution and disperse in the early hydration reaction phase; the acceleration of hydration reactions and stable phase in the late.

Preparation and Experimental Study on a New Type of Exterior Wall Putty

With the rapid development of construction industry, the amount of architectural coatings, especially exterior wall coatings, is growing year by year. However, more common problems of construction quality arise with the increase of project amount. Exterior wall putty is leveling material of the protective layer, and putty fitting for external thermal insulation system should have a high bonding strength, good performance of crack resistance and excellent resistance to water. The basic material in this paper is cement and coarse whiting, talcum powder and quartz powder are the fillers. Then the basic mix of putty will be got through orthogonal experimental design. In order to improve the performance and research inorganic materials and associated auxiliary for external wall putty performance impact, pasty exterior wall putty can be prepared through mechanical mixing and by adding some relevant inorganic materials and auxiliaries. Results indicate that this kind of exterior wall putty is easy to burnish the powder and have good performances of workability, water resistance, high bonding strength and dynamic crack resistance. Which has better performances than that sold in market, especially for the performances of bond strength, dynamic crack resistance and water absorpution.

Influence of Structure Unit and the Distribution on the Low-Velocity Impact Property of the 3D Woven Composites

In this paper, the low-velocity impact properties of the 3D woven composites were tested. Through the study on the relationship of absorbed energy and material structure, the impact resistance of the composites has been discussed. The research results show that the low-velocity impact resistance of quasi-orthogonal composites is the best, the low-velocity impact resistance of orthogonal composites is the worst and angle tangled of interlayer joint composites stand somewhere between the two. Adding quasi-orthogonal unit into the structure, the low-velocity impact property of the composites can be enhanced efficiently. On the other hand, if the unit distribution of the enforced fabric is changed, the break time and break point will be changed. But the effect on the total absorbed energy is not obvious.

Basic Mechanics Characters of Recycled Fine Aggregate Concrete

In this article, the basic mechanical characters of recycled fine aggregate concrete (RFAC) are studied, and the relationships of recycled fine aggregate (RFA) content, minimum particle size and water content with them are also discussed according to results of cubic compressive strength （f¬¬cu）, flexural strength （ff）, splitting tensile strength（fts）, axial compressive strength（fc）and Yang’s modulus （Ec）. The results indicate that the use of RFA will induce mechanical properties of RFAC to deteriorate, and the deteriorated trend of it become more obviously with RFA content increased and minimum particle size reduced, in addition to, the early compressive strength of RFA develop slowly. The RFAC elastic modulus is significantly lower than ordinary concrete, besides, RFA on elastic modulus was significantly affected than other mechanical properties.

Study on the Resin Curing Time and the Mechanical Properties of the Composites

In order to study the curing characteristics of common resins including bisphenol-A epoxy vinyl ester resin, phenolic epoxy vinyl ester resin and unsaturated polyester resin, the curing time of three resins was tested using cobalt naphthenate as accelerator and methyl ethyl ketone peroxide as curing agent. The results showed that the resin curing time reduces with the experimental temperature rising; in order to control the curing time at about 25 minutes when the experimental temperature is 23°C, the curing agent adding proportion of bisphenol-A epoxy vinyl ester resin, unsaturated polyester resin and phenolic epoxy vinyl ester resin are respective about 0.7%, 0.5% and 1.8%. The composites made by bisphenol-A epoxy vinyl ester resin have excellent tensile strength and composites made by phenolic epoxy vinyl ester resin have best bending strength.

Technical Study of Fly Ash Three-Slag Base Course Materials Modified with Washed-Out Slurry

Based on the effects of fly ash three-slag mixture by industrial solid wastes (washed-out slurry),the paper has been approached to the modified problems of the fly ash three-slag mixture. The strength and durability tests suggest that the fly ash three-slag mixture modified with washed-out slurry have the features of high-early-strength and higher durability.

Experimental Study of the Soundness and Compatibility of Baosteel Steel-Slag Powder Applied in Cement Concrete

To reduce the cost and improve concrete performance, massive admixtures were needed to be added to the concrete. With the research going, the high quality mixture is increasingly becoming the indispensable concrete component. The steel slag powder is the steel-slag comprehensive utilization technical commanding point compared with the level of the steel slag application nowadays in the world. In order to develop the application of the steel slag fine powder in cement concrete domain, this article analyzes autoclaved soundness of the Baosteel steel-slag fine powder as well as the compatibility of it with the cement and the concrete admixtures.

The Relationship between Furized Gypsum Fly Ash Three Constituent Mixture Subtle Structure and Performance

The paper aims to study the influence of furized gypsum fly ash three constituent mixture subtle structure to performance by analyzing furized gypsum fly ash three constituent IR, SEM, X-ray phase and DTA. The results show that the reason why furized gypsum fly ash three constituent has the characteristics of high strength in the early stage and good endurance quality is that furized gypsum fly ash concrete has the double actived effect of alkali-activated and sulfate-activated. The development of sclerotium strength mainly relies on ettringite and hydrated calcium silicate gel. During the process of hydration, ettringite and CSH gel hydration increase continuously, hardened structure becomes dense and strength continues to increase.