Papers by Author: Jun Long Zhou

Abstract: This paper studies the effect of fly ash on expansion properties of mortar and concrete with the addition of expansive agents. It concludes that fly ash have different influence on the expansive effect of concrete with addition of expansive agents, the original fly ash hardly has any effect on the expansion properties of mortar and concrete with the addition of expansive agents. But, the milled fly ash has great effect on expansion properties of mortar and concrete with the addition of expansive agents, and the more the milled fly ash is added, the greater the effect is. Even if content of the original fly ash is over 30 percent, the value of expansive rate of mortar and concrete with addition of the original fly ash is as high as that of mortar and concrete without addition of fly ash. When the content of milled fly ash is over 10 percent, the effect on the expansion properties is weakened. When fly ash and expansive agent added to concrete at the same time, fly ash the original fly ash must be used.

Abstract: This paper compares the properties of concrete made by reclaimed fine aggregate with those made by other fine aggregate. Although the properties of reclaimed fine aggregate and other kinds of fine aggregate are different, especially the strength of reclaimed fine aggregate is lower than that of manufactured sand. It is concluded that the fluidity, the strength and the elastic modulus of concrete made by reclaimed fine aggregate are almost similar to those made by other fine aggregate. When it comes to the making of concrete, reclaimed fine aggregate can serve as a substitute for other aggregate. Moreover, it can enhance resources utilization and reduce environmental pollution.

Abstract: It is inevitable for steel reinforcement to be corroded when mixed with seawater-and-seasand concrete. In order to improve steel corrosion protection properties of seawater-and-seasand concrete, reduce the chloride ion’s attack on steel reinforcement in structural concrete and lengthen the steel reinforcement’s service time, this paper presents an experimental study on whether admixtures like fly ash, slag and metakaolin in the seawater-and-seasand could retard the corrosion to steel reinforcement and provide protection to steel reinforcement in seawater-and-seasand concrete. The results indicated that metakaolin had a significant anti-corrosion effect and greatly enhanced the steel corrosion protection properties of seawater-and-seasand concrete whereas both fly ash and slag did not appear to have any obvious influence on curbing the corrosion of steel reinforcement.