Papers by Keyword: Long Term Performance

Abstract: This paper is concerned with the long-term performance of geo-textile (GT) composites in terms of creep deformation and frictional properties. Composites of PVA GT and HDPE GM were made to investigate the advanced properties of long-term performance related to waste landfill applications. The same experiments were also performed for typical polypropylene and polyester GT and compared to PVA GT/HDPE GM composites. The main purpose of this study is to develop high performance GT composites with GM by using PVA GT which is capable of improving frictional property and thus enhances long-term performance of GT composites. In the present experiments, GT composites of PVA GT/HDPE GM, PVA GT of 600, 1000, 1500, 2000g/m2 and HDPE GM were prepared in thermal bonding process. Polyester and polypropylene GT were also made in needle punching process. The creep deformation of GT composites was measured and evaluated in accordance with ASTM D5262. Frictional characteristics of GT composites tested in this study were conducted with compact direct shear apparatus in accordance with ASTM D5321. It was concluded from the present experimental study that friction coefficient of GT composites is relatively large compared with those of polyester and polypropylene non-woven GT as long as the friction media has similar size to the particles of domestic standard earth. In the event that 20% of the maximum tensile strength was added to polypropylene and polyester non-woven geo-textiles, creep deformation reached to 10% or higher, making it even impossible to find reduction factor.

Abstract: The slag-alkali is used to activate the activity of higher calsium fly ash. By the designs of the mixture ratio and the quadratic regression orthogonal design, the best combination is sought out. Several mixture factors which affect the rule of the concrete material properties and long term performance are researched. The mathematic models which are set up by the mixture ratio design with the quadralic regression orthogonal design can be effective. The precision is high. The strength of the concrete of slag-alkali fly ash was still increasing after 8 year. The dispersion degree of those specimens is small. The SEM photo of cracked specimen and early concrete specimen shows the surface of fly ash in 7 days concrete is slick and that in 8 years old specimen has been enwrapped tightly by much hydrate plant.