The primary objective of this paper was to study the mechanical properties and durability of the cement stabilized gravel by different compact method. The influence of rubber particle content on mechanical properties ...The primary objective of this paper was to study the mechanical properties and durability of the cement stabilized gravel by different compact method. The influence of rubber particle content on mechanical properties of samples was studied by compaction tests and freezing thawing recycle tests. Pore structure and fractal characteristic of mixture were analyzed quantitatively using mercury intrusion porosimetry （MIP）. X-ray diffraction （XRD） was adopted to identify the composition phases. The morphology analysis in micro scale and elemental analysis of samples were carried out by scanning electron microscope （SEM）. The optimum compressive strengths of rubber cement stabilized gravel （RCSG） with static compaction method and with vibratory compaction method were obtained by controlling compaction degree and vibration time, respectively. From the compaction tests, the vibratory compaction method is preferred compared with the static compaction method as better compressive strength can be improved by about 340%-360%. Besides, test results also reveal that compressive strength of samples with vibratory compaction method or static compaction method will decrease with the rubber particle bulk content increasing. The freezing thawing recycle tests indicate that freezing thawing resistance has been improved （frozen stability coefficient K has been increased from 0.89 to 0.97） by the addition of rubber particles. MIP tests show that the mean pore diameter and porosity of mixture have been increased from 70 to 250 nm and 9% to 24% respectively, with the rubber particles content increasing. Component analysis shows that the calcium silicate hydrate （CSH） is the predominant hydrate product with or without the addition of rubber particles.展开更多
Aim of present work is to replace asbestos in thermal insulation by another percentage of non-toxic fillers such as silica. Different formulations of fillers were prepared and added to Nordel (Trade name assigned for ...Aim of present work is to replace asbestos in thermal insulation by another percentage of non-toxic fillers such as silica. Different formulations of fillers were prepared and added to Nordel (Trade name assigned for ethylene, propylene and 1, 4-hexadiene elastomers). The physical and mechanical properties (after and before aging), and thermal properties of the prepared samples were investigated. The objective was to choose a new formulation with properties that resemble as closely as possible those of the originally used in thermal insulation. After measuring the properties of tensile strength, elongation, hardness, specific gravity, compression set, rebound resilience, thermal conductivity, and initial and final decomposition temperatures, the sample that had values very close to those of the originally used in thermal insulation was chosen and recommended to be used. From comparison it was found that EPDM rubber with 50% silica gave the optimum properties closest to the originally used.展开更多
基金Funded by the National Natural Science Foundation of China(No.51008076)
文摘The primary objective of this paper was to study the mechanical properties and durability of the cement stabilized gravel by different compact method. The influence of rubber particle content on mechanical properties of samples was studied by compaction tests and freezing thawing recycle tests. Pore structure and fractal characteristic of mixture were analyzed quantitatively using mercury intrusion porosimetry （MIP）. X-ray diffraction （XRD） was adopted to identify the composition phases. The morphology analysis in micro scale and elemental analysis of samples were carried out by scanning electron microscope （SEM）. The optimum compressive strengths of rubber cement stabilized gravel （RCSG） with static compaction method and with vibratory compaction method were obtained by controlling compaction degree and vibration time, respectively. From the compaction tests, the vibratory compaction method is preferred compared with the static compaction method as better compressive strength can be improved by about 340%-360%. Besides, test results also reveal that compressive strength of samples with vibratory compaction method or static compaction method will decrease with the rubber particle bulk content increasing. The freezing thawing recycle tests indicate that freezing thawing resistance has been improved （frozen stability coefficient K has been increased from 0.89 to 0.97） by the addition of rubber particles. MIP tests show that the mean pore diameter and porosity of mixture have been increased from 70 to 250 nm and 9% to 24% respectively, with the rubber particles content increasing. Component analysis shows that the calcium silicate hydrate （CSH） is the predominant hydrate product with or without the addition of rubber particles.
文摘Aim of present work is to replace asbestos in thermal insulation by another percentage of non-toxic fillers such as silica. Different formulations of fillers were prepared and added to Nordel (Trade name assigned for ethylene, propylene and 1, 4-hexadiene elastomers). The physical and mechanical properties (after and before aging), and thermal properties of the prepared samples were investigated. The objective was to choose a new formulation with properties that resemble as closely as possible those of the originally used in thermal insulation. After measuring the properties of tensile strength, elongation, hardness, specific gravity, compression set, rebound resilience, thermal conductivity, and initial and final decomposition temperatures, the sample that had values very close to those of the originally used in thermal insulation was chosen and recommended to be used. From comparison it was found that EPDM rubber with 50% silica gave the optimum properties closest to the originally used.
