高韧性植物纤维增强水泥基材料单轴拉伸试验研究
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摘要
从绿色经济角度出发,以获得较高韧性为目的,采用短切内掺及长纤维分层平铺两种制备工艺,通过单轴拉伸试验获得四种植物纤维增强水泥基材料的拉伸特性,并对材料成本进行分析。试验结果表明:内掺短切苎麻纤维与剑麻纤维试件虽表现出应变软化特征但在开裂后具有较好的应力水平保留率。竹原、大麻、剑麻及苎麻纤维分层平铺试件均表现出明显应变硬化特征且极限拉应变均达到2%以上,而剑麻纤维分层平铺试件拉伸性能优越且成本较低有利于进一步的研究与推广应用。
From the point of view of developing green and low cost materials,four kinds of vegetable fibers,including bamboo fiber, sisal fiber, hemp fiber and ramie fiber, were used to reinforce cementitious composites to get higher ductility. Specimens were casted with random short fiber and aligned long fiber. Direct tensile performance of specimens was tested and analyzed. Also the cost of materials was analyzed. The results show that specimens with short ramie and sisal fiber perform strain softening but better stress retention rate after cracking. Furthemore,all specimens with aligned long fiber perform strain hardening characteristics and the ultimate tensile strain can reach above 2%. In particular aligned long sisal fiber reinforced specimens show excellent tensile property and low cost,which would be more favorable to further development and application.
From the point of view of developing green and low cost materials,four kinds of vegetable fibers,including bamboo fiber, sisal fiber, hemp fiber and ramie fiber, were used to reinforce cementitious composites to get higher ductility. Specimens were casted with random short fiber and aligned long fiber. Direct tensile performance of specimens was tested and analyzed. Also the cost of materials was analyzed. The results show that specimens with short ramie and sisal fiber perform strain softening but better stress retention rate after cracking. Furthemore,all specimens with aligned long fiber perform strain hardening characteristics and the ultimate tensile strain can reach above 2%. In particular aligned long sisal fiber reinforced specimens show excellent tensile property and low cost,which would be more favorable to further development and application.
引文
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[7]徐世烺,李贺东.超高韧性水泥基复合材料研究进展及其工程应用[J].土木工程学报,2008,41(6):45-60.
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[9] Li Z,Wang L,Wang X. Compressive and flexural properties of hemp fiber reinforced concrete[J]. Fibers and Polymers,2004,5(3):187-197.
[10] Savastano H,Santos S,Radonjic M,et al. Fracture and fatigue of natural fiber-reinforced cementitious composites[J]. Cemment and Concrete Composites,2009,31(4):232-243.
[11]谢晓丽.植物纤维改性水泥基复合材料的制备与力学性能研究[D].成都:西南交通大学,2016.
[12] Silva F D A,Mobasher B,Filho R D T. Cracking mechanisms in durable sisal fiber reinforced cement composites[J]. Cement and Concrete Composites,2009,31(10):721-730.
[13] Yun H D,Kim S W,Lee Y O,et al. Tensile behavior of synthetic fiber-reinforced strain-hardening cement-based composite(SHCC)after freezing and thawing exposure[J]. Cold Regions Science and Technology,2011,67(1):49-57.
[2]陈润锋,张国防,顾国芳,等.我国合成纤维混凝土研究与应用现状[J].建筑材料学报,2001,4(2):167-173.
[3] Li V C,Leung C K Y. Steady state and multiple cracking of short random fiber composites[J]. ASCE Journal of Engineering Mechanics,1992,118(11):2246-2264.
[4] Li V C,Mishra D K,Wu H C. Matrix design for pseudo strain-hardening fiber reinforced cementitious composites[J]. Materials and Structures,1995,28(10):586-595.
[5] Wu R X,Wang P G,Wittmann F H,et al. Composition and properties of SHCC; partⅠ:influence of composition of cement-based matrix on strain capacity and crack distribution[J]. Restoration of Buildings and Monuments,2014,20(2):103-110.
[6] Li V C,张亚梅.高延性纤维增强水泥基复合材料的研究进展及应用[J].硅酸盐学报,2007,35(4):531-536.
[7]徐世烺,李贺东.超高韧性水泥基复合材料研究进展及其工程应用[J].土木工程学报,2008,41(6):45-60.
[8] Fernando P T,Said J. Cementitious building materials reinforced with vegetable fibres:a review[J]. Construction and Building Materials,2011,25(2):575-581.
[9] Li Z,Wang L,Wang X. Compressive and flexural properties of hemp fiber reinforced concrete[J]. Fibers and Polymers,2004,5(3):187-197.
[10] Savastano H,Santos S,Radonjic M,et al. Fracture and fatigue of natural fiber-reinforced cementitious composites[J]. Cemment and Concrete Composites,2009,31(4):232-243.
[11]谢晓丽.植物纤维改性水泥基复合材料的制备与力学性能研究[D].成都:西南交通大学,2016.
[12] Silva F D A,Mobasher B,Filho R D T. Cracking mechanisms in durable sisal fiber reinforced cement composites[J]. Cement and Concrete Composites,2009,31(10):721-730.
[13] Yun H D,Kim S W,Lee Y O,et al. Tensile behavior of synthetic fiber-reinforced strain-hardening cement-based composite(SHCC)after freezing and thawing exposure[J]. Cold Regions Science and Technology,2011,67(1):49-57.