Papers by Keyword: Polypropylene (PP) Fiber

Abstract: Base on the data that gained from pullout test of Polypropylene fiber, multi-factor regression analysis considering water cement ratio and age of cement matrix, length and angle of embedded fiber was carried out. Then, a practical function of pullout force-displacement was proposed, which is well agreed with the test results.

Abstract: The successive civilengineering disasters in recent years make the use of geomaterial for disaster prevention popular. Geogrids, one type of geo-material, function as soil reinforcement. This study uses polypropylene (PP) fibers to wrap high strength polyester (HSPET) fibers, forming the PP/HSPET fasciated yarn. PP fibers are acid-resistant and alkali-resistant, and thus serve as the skin of the fasciated yarn. HSPET fibers, the core of the fasciated yarn, protect and prolong the service life of the resulting geo-material products. Finally, the influence of mechanical parameters on the appearance and strength of the fascinated yarn is explored.

Abstract: This paper is focused on the method for improving capability of anti-sulfate corrosion of concrete. Based on the performance characteristics of mineral admixture, propose a method that mixing concrete with complex multi-mineral admixture to improve the effect of anti-sulfate corrosion. Finally, the ability of anti-sulfate corrosion and anti-dry-wet cycle, in different case, is studied and compared. The results show that concrete mixed with complex multi-mineral admixture is advantageous to improve the anti-sulfate corrosion effects of the concrete. The proportion of mineral admixtures has significant influence on the anti-sulfate corrosion effect. As the silica fume and slag content increased, the fly ash content decreased, the ability of anti-sulfate corrosion enhanced.

Abstract: Experiments were carried out to investigate the splitting properties of hybrid fiber reinforced concrete after exposure to elevated temperatures. Based on the experimental observation, the effect of steel fiber dosage, polypropylene (PP) fiber dosage and strength grade of concrete on the residual splitting strength of the concrete after being subjected to high temperature was systematically analyzed. Test data indicated that high temperature caused significant deterioration in the splitting strength of concrete; the addition of PP fiber and steel fiber could all effectively improve the residual splitting properties of concrete; the optimum amount of PP fiber and steel fiber were identified respectively; the degree of strength loss of concrete with different strength grades was very close to each other. A theoretical equation was proposed to predict the residual splitting strength of concrete after being heated to temperatures up to 800°C.

Abstract: Experiments were carried out to investigate the dry-shrinkage of masonry mortar affected by mass content of polypropylene fiber. The results show that proper content of polypropylene fiber is helpful to effectively reduce dry-shrinkage of mortar especially in early age, the reduction relates to water to cement ratio of mortar. Meanwhile, the relationships of water to cement ratio and content of polypropylene fiber in affecting dry-shrinkage of masonry mortar are analyzed, which can be as reference for selecting such optimum values as water to cement ratio and content of polypropylene fiber in practices.

Abstract: Experiments were carried out to investigate such basic properties as workability and strength of masonry cement mortar affected by mass content of polypropylene fiber. The results show that proper mass content of polypropylene fiber is helpful for effectively adjusting consistency and layering to bring better workability of fresh mortar, the relative higher bending strength of mortar can be got by admixing reasonable mass content of polypropylene fiber while slight improved compressive strength reaches. The relationships of water to cement ratio and mass content of polypropylene fiber in affecting these basic properties of masonry mortar are analyzed, which can be as reference for selecting optimum water to binder ratio and mass content of polypropylene fiber in practices.

Abstract: Low tensile strength and high brittleness are the inherent defects of cement-based composites. So improving the toughness effectively is an urgent need for developing high-performance cement materials. The aim of this study is to study the toughening effect by mixing CaCO₃ whiskers and polypropylene fibers in cement mortar. The results showed that CaCO₃ whiskers could increase the split tensile strength of cement mortar of 28d age by 26.2% at maximum with the whisker content of 10wt.%; when CaCO₃ whiskers content was 10wt.% and polypropylene fibers content was 0.20vol.%, the split tensile strength of cement mortar was increased by 21.1% at 28d age; when the fiber length was 19mm, the composite toughening effect of whiskers and fibers was more effective. The toughening mechanisms of CaCO₃ whiskers and polypropylene fibers in cement mortar were also discussed.

Abstract: Polypropylene fibrous concrete is a new kind of composite material. Polypropylene fiber leads to an increase in the resisting strength, cracking resistance performance, resistance to impact performance and permeability reducing performance of the concrete, thus reduces the shrinking and deformation of the concrete. This paper uses the method of numerical analysis, assisted by the software of finite element analysis, makes both static and dynamic analysis on the polypropylene fibrous concrete ditch with different volume mixing. It results in the stress and strain table of the head and base plates of the polypropylene fibrous concrete ditch in the case of 0.1%, 0.5%, and 1% volume mixing of polypropylene fibers. The paper provides technological basis for formation design of the polypropylene fibrous concrete materials, and laids technological foundation for the further developments of polypropylene fibrous concrete in hydraulic engineering.

Abstract: The basic mechanical properties of fly ash fiber concrete were tested. The influences to the compressive strength, splitting tensile strength and compressive modulus of elasticity of fiber concrete by water-cement ratio, dosage of fly ash and other factors were analyzed. The influence mechanism of fly ash to concrete is discussed. The results indicate that with the increase of the dosage of fly ash, the early strength of double-doped concrete is reduced, while the later strength of concrete was obviously increased.

Abstract: In order to study the durability of Polypropylene fiber concrete, indoor artificial methods were used to simulate dry-wet cycle and deicer-frost damage. The results indicated that amounts of polypropylene fibers increase the flexural strength of concrete slightly. The chloride penetration depth increased as the cycles of dry-wet was increased, adding 0.1% PPF into concrete have the prefect resistance of Cl^- penetration. Under salt freezing cycle, the deicer-scaling resistance of concrete is reduced by the addition of Polypropylene fiber. The corner of concrete has the largest Cl^- penetration area.