作者：王欣
作者单位：山西工程科技职业大学工程管理系，山西 太原 030031
关键词：高强再生混凝土;砂率;再生粗骨料取代率;力学性能;干燥收缩
摘要：
再生混凝土的综合利用可缓解矿石资源压力，实现低碳循环可持续经济。该研究采用砂率（34%，36%，38%，40%）和再生骨料替代率（0，30%，50%）为控制变量，以抗压强度、抗拉强度、抗折强度及干燥收缩变形为指标，详细探讨砂率和再生骨料替代率对高强再生混凝土的性能影响规律。研究表明：高强再生混凝土的力学强度均随着再生粗骨料的增加而逐渐降低，适量的砂率会产生高强度的再生混凝土坍落度，可以提升再生混凝土的密实度，脆性和塑性变形能力，并提高其力学强度。高强度再生混凝土的干缩率变化率在90 d后逐渐趋于稳定，砂率和干缩率的变化呈良好的线性关系。增加砂的比例能在一定程度上降低再生粗骨料对高强度再生混凝土干缩的影响。
research on the effect of sand ratio on the mechanical and drying shrinkage properties of high strength recycled concrete
wang xin
department of engineering management, shanxi vocational university of engineering science and technology, taiyuan 030031, china
abstract: the comprehensive utilization of recycled concrete can alleviate the pressure of ore resources and achieve a sustainable economy with a low carbon cycle. in this study, sand rate (34%, 36%, 38%, 40%) and recycled aggregate replacement rate (0, 30%, 50%) were used as control variables. compressive strength, tensile strength, flexural strength, and the drying shrinkage deformation is used as an index. the influence of sand rate and recycled aggregate replacement rate on the performance of high-strength recycled concrete is specifically explored. studies have shown that a moderate amount of sand yields high slump in recycled concrete. with the increase of recycled coarse aggregate, the compressive, tensile and flexural strength of high-strength recycled concrete decreases. proper sand ratio can improve the compactness, brittleness and plastic deformation ability of high-strength recycled concrete, and increase its mechanical strength. the change rate of dry shrinkage rate of high-strength recycled concrete gradually stabilized after 90 days, and the change of sand speed and dry shrinkage rate showed a good linear relationship. increasing the proportion of sand may reduce the effect of recycled coarse aggregate on dry shrinkage of high-strength recycled concrete to a certain extent.
keywords: high strength recycled concrete;sand ratio;replacement rate of recycled coarse aggregate;mechanical properties;drying shrinkage
2023, 49(4):159-164 收稿日期: 2021-06-30;收到修改稿日期: 2021-09-01
基金项目:
作者简介: 王欣(1982-),女,黑龙江佳木斯市人,讲师,主要从事土木工程管理方面的研究工作
参考文献
[1] 潘威, 张韶华, 甘春燕. 再生粗骨料对c80高强混凝土性能的影响[j]. 公路, 2019, 64(12): 255-259
[2] 盛朝晖, 牛培飞, 游文斐. 多因素对再生混凝土力学性能及抗冻性的影响[j]. 中国测试, 2021, 47(2): 140-148
[3] 肖建庄, 李标, 杨钱荣, 等. 复合改性再生混凝土抗氯离子渗透性能[j]. 混凝土与水泥制品, 2019(10): 1-5
[4] 孔祥清, 鲍成成, 高化东, 等. 钢-聚丙烯混杂纤维再生混凝土力学性能试验研究[j]. 混凝土, 2017(11): 105-109
[5] 肖建庄, 陈祥磊, 李标, 等. 纳米sio2和粉煤灰复掺对再生混凝土性能的影响[j]. 建筑科学与工程学报, 2020, 37(1): 26-32
[6] 李晓晶. 再生粗骨料玄武岩大纤维混凝土梁的抗弯性能试验研究[j]. 新型建筑材料, 2021, 48(6): 59-63
[7] 孙道胜, 李泽英, 刘开伟, 等. 再生粗骨料的形态及缺陷对再生混凝土干燥收缩和力学性能的影响[j]. 材料导报, 2021, 35(11): 11027-11033 11056
[8] 段珍华, 侯少丹, 潘智生, 等. 再生细骨料混凝土流变性及其对强度和耐久性的影响[j]. 建筑结构学报, 2020, 41(s2): 420-426
[9] yang s, lee h. freeze -thaw resistance and drying shrin kage of recycled aggregate concrete proportioned by the modified equivalent mortar volume method[j]. international journal of concrete structures & materials, 2017, 11(4): 617-626
[10] 罗伯光, 覃荷瑛. 矿物掺和料对再生混凝土力学性能的影响[j]. 中外公路, 2014, 34(2): 268-273
[11] 苏卿. 砂率对c30再生混凝土干燥收缩开裂性能评价的影响[j]. 混凝土, 2017(12): 116-119
[12] 边金明, 安新正, 芈峥, 等. 基于砂率的富含砖粒再生混凝土基本性能试验研究[j]. 河北工程大学学报(自然科学版), 2020, 37(2): 14-17
[13] 仇影, 丁蓓, 郑春扬, 等. 砂率对c30-c50混凝土强度及工作性能的影响[j]. 硅酸盐通报, 2016, 35(10): 3486-3491
