Use of polyethylene terephthalate as an Anti-stripping agent in GLASSPHALT

This study evaluates the use of polyethylene terephthalate (PET) in Glassphalt aimed at increased bonding effect of bitumen, reduced stripping and increased in stability and strength. Control mix were prepared with bitumen content of 5.0, 5.5, 6, 6.5 and 7% to determine the optimum bitumen content (OBC). Optimum glass content (OGC) was obtained from samples prepared with glass content of 5, 10, 15, 20, and 25% replacement by weight of fine aggregates. The OBC and OGC were used prepare samples with PET content of 2, 4, 6, 8, and 10% by weight of the OBC. The optimum PET content had a higher stability value of 5.8kN and higher air void of 3.8% when compared to the control mix. Stripping value tests showed that PET modified glassphalt had 0% stripping after a period of 48 hours. Waste PET of 6.6% in 16% glassphalt is recommended for use as an anti-stripping agent.

Properties of Concrete with Waste Glass Powder (Gp) as Fine Aggregate Replacement

In the present research, the feasibility of using waste glass as replacement for natural river sand was investigated. Glass wastes dumped in landfill pose environmental pollution and research on its reuse in construction industries need to be carried out . An experimental work was performed to study the slump , unit weight, compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, ultrasonic pulse velocity, dry density and chloride ion penetration test at different curing ages at 7, 14 and 28 days of concrete. Investigation on concrete properties with various % of glass powder (0%, 5%, 10%, 15% and 20% ) were done on fresh and hardened concrete. The complete stress-strain behaviour, mechanical strength and durability properties of concrete with partial replacement of natural river sand by glass powder were investigated through standard tests.The optimum glass powder content is found out by testing the specimens prepared using different grades of concrete (M20, M30, M40,M50 and M60). All the fresh concrete mixes were tested also for the workability properties by conducting slump cone tests. According to the test results, it is observed that the slump value of fresh concrete increase gradually with % of glass powder upto 40% replacements. The gradual increase in compressive strength, flexural strength and split tensile strength with the addition of waste glass powder upto 30% was observed. The addition of 40% and 50% replacements, the strength values of concrete are comparable with that of the control mix. The density and modulus of elasticity of concrete also gradually increases from 0% to 50% addition of glass powder in the concrete. The Rapid Chloride Penetration Test (RCPT) test results show that the chloride penetration rate is considerably reduced with addition of glass powder and permeability properties of concrete is enhanced upto 50% replacement levels. In order to prepare the concrete with compressive strengthThe optimum glass powder content is found to be 50% can be used as the replacement material for fine aggregates without much compromise on the strength and durability properties and to achieve economic and environmental benefits

The influence of Nb and Zr on glass-formation ability in the ternary Fe–Nb–B and Fe–Zr–B and quaternary Fe–(Nb,Zr)–B alloy systems

Glass-forming ability (GFA) in relation to microstructure evolution in the ternary Fe–Nb–B and Fe–Zr–B and quaternary Fe–(Nb,Zr)–B systems was systematically studied in a three-dimensional composition space. Through navigating, it was revealed that alloys with the optimum glass-forming ability (GFA) are coupled with composition regions surrounded by competing crystalline phases. Alloys Fe71Nb6B23, Fe77Zr4B19, and Fe71(Nb0.8Zr0.2)6B23 were illustrated to be the best glass formers in the ternary Fe–Nb–B and Fe–Zr–B systems and the quaternary Fe–(Nb,Zr)–B system, respectively, with a critical size for amorphous formation up to 2 mm. They were compared with the theoretical predictions on the basis of an efficient dense-packing model, and good agreements were obtained.

Formation of Bulk Metallic Glasses and Their Composites

A great expansion in the number of alloy compositions known to give bulk metallic glasses (BMGs) has occurred in recent years. This progress is reviewed, and factors contributing to glass-forming ability are discussed. Practical strategies for pinpointing compositions with optimum glass-forming ability are presented, with examples of their use. Consideration is also given to the wide range of possibilities for BMG-based composites.