不同类型天然纤维对混凝土力学性能的影响研究

Study on the influence of different types of natural fibers on the mechanical properties of concrete

为了改善传统混凝土材料抗拉抗折强度低以及脆性较强的问题,以剑麻纤维、苎麻纤维、竹纤维和亚麻纤维4种不同类型的天然纤维为研究对象,考察了天然纤维掺量对混凝土力学性能的影响。试验结果表明:随着天然纤维掺量的不断增大,混凝土试件的抗压强度值逐渐降低,而劈裂抗拉强度和抗折强度值则均呈现出“先升高后降低”的趋势。在设计的混凝土配合比条件下,剑麻纤维和亚麻纤维对混凝土试件抗拉和抗折性能的改善效果明显优于竹纤维和苎麻纤维,并且其对混凝土抗压强度的影响也相对较小。当剑麻纤维的掺量为0.5%时,可使混凝土试件的劈裂抗拉强度和抗折强度分别提升20.24%和18.26%,而当亚麻纤维的掺量为2.0%时,可使混凝土试件的劈裂抗拉强度和抗折强度分别提升21.45%和28.13%。研究结果认为天然纤维的掺入能够明显提高混凝土试件的抗拉和抗折性能,但同时会降低其抗压强度。

In order to improve the low tensile and flexural strength and strong brittleness of traditional concrete materials,four different types of natural fibers,sisal fiber,ramie fiber,bamboo fiber and flax fiber,were taken as research objects to investigate the influence of natural fiber content on the mechanical properties of concrete.The test results show that with the increase of natural fiber content,the compressive strength of concrete specimens gradually decreases,while the splitting tensile strength and flexural strength show a trend of“first increasing and then decreasing”.Under the concrete mix ratio designed,sisal fiber and flax fiber can significantly improve the tensile and flexural properties of concrete specimens than bamboo fiber and ramie fiber,and their effects on the compressive strength of concrete are relatively small.When the content of sisal fiber is 0.5%,the splitting tensile strength and flexural strength of concrete specimens can be increased by 20.24%and 18.26%respectively,while when the content of flax fiber is 2.0%,the splitting tensile strength and flexural strength of concrete specimens can be increased by 21.45%and 28.13%respectively.The results show that the addition of natural fibers can significantly improve the tensile and flexural properties of concrete specimens,but at the same time reduce their compressive strength.