CAJ | 학술논문

为研究初始裂缝尺寸及材料组成特性等因素对混凝土断裂韧度的影响,通过混凝土切口梁三点弯曲试验,探讨了相对切口深度、粗骨料最大粒径及分布和水灰比等因素改变时混凝土断裂韧度的变化规律.结果表明:相对切口深度对混凝土断裂韧度有一定影响,不同相对切口深度下,混凝土缺口敏感性不同;随着粗骨料最大粒径增加,混凝土断裂韧度呈增大趋势,断面二值图和粗骨料水平投影面积率可有效反映粗骨料对混凝土断裂韧度的影响;随着水灰比减小,混凝土断裂韧度逐渐增加;混凝土断裂韧度与切口梁试件裂缝前端阻裂带的“强弱”有关.在分析试验结果的基础上,建立了多因素影响下混凝土断裂韧度的计算模式,在混凝土配合比已知的情况下,该模式可用于分析诸因素对混凝土断裂韧度的影响并预测混凝土断裂韧度.
위연구초시렬봉척촌급재료조성특성등인소대혼응토단렬인도적영향,통과혼응토절구량삼점만곡시험,탐토료상대절구심도、조골료최대립경급분포화수회비등인소개변시혼응토단렬인도적변화규률.결과표명:상대절구심도대혼응토단렬인도유일정영향,불동상대절구심도하,혼응토결구민감성불동;수착조골료최대립경증가,혼응토단렬인도정증대추세,단면이치도화조골료수평투영면적솔가유효반영조골료대혼응토단렬인도적영향;수착수회비감소,혼응토단렬인도축점증가;혼응토단렬인도여절구량시건렬봉전단조렬대적“강약”유관.재분석시험결과적기출상,건립료다인소영향하혼응토단렬인도적계산모식,재혼응토배합비이지적정황하,해모식가용우분석제인소대혼응토단렬인도적영향병예측혼응토단렬인도.
@@@@In this paper,the effects of the initial crack size and mix proportions of concrete upon fracture toughness of concrete (KIC) were studied. Through the three-point bending test on the specimens of con?crete,the effects of influencing factors including notch depth (a0/h),maximum particle diameter and distri?bution of coarse aggregate (dmax) and water-cement ratio (W/C) upon KIC were studied. The results show that a0/h has some effect on KIC. The notch sensitivities of concrete are different at different a0/h. KIC tends to increase as dmax increases. The binary image of cross section and the horizontal projection area ratio (D) reflect the effect of coarse aggregate on KIC effectively. KIC increases as W/C decreases. KIC is related to the magnitude of cracking resistance capacity of the band for cracking resistance at crack tip field. Based on the test results, the calculation model under the influencing factor is established for calculating KIC, and this calculation model can be used to analyze the effect of influencing factor upon KIC and predict KIC when mix proportions of concrete are known.