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摘要: 为降低超高性能混凝土(UHPC)收缩和开裂风险, 进行了5组不同粗集料掺量(质量分数分别为0、12.5%、22.5%、32.5%和42.5%)的UHPC的自收缩、基本材性(抗压强度、抗拉强度和弹性模量)、集料级配和圆环约束收缩等试验, 分析了粗集料掺量和集料级配对UHPC自收缩和基本材性的影响, 并采用提出的收缩开裂应力相对差值评价粗集料的掺入对UHPC收缩开裂的影响; 进行了有、无粗集料UHPC在圆环约束下的开裂性能试验与对比分析, 验证粗集料掺入对减小UHPC收缩开裂的有效性, 并给出UHPC中粗集料掺量和最大粒径限制的建议。研究结果表明: 随着粗集料掺量的增加, UHPC早期自收缩量降低, 最大降幅近20%;粗集料对UHPC的弹性模量、抗压强度和抗拉强度等的影响程度与其掺量和级配有关, 当粗集料掺量为22.5%时, 其级配曲线几乎全部处于富勒氏与泰勃特曲线范围内, 是5组材料中堆积最紧密的一组, 对UHPC弹性模量与抗压强度提高最为显著, 对抗拉强度的降低幅度影响最小; 当粗集料掺量为22.5%时, UHPC收缩开裂应力相对差值最大为1.31 MPa, 为试验中的最合理掺量, 可有效降低收缩开裂风险; 与未掺粗集料的UHPC相比, 圆环约束下掺有22.5%粗集料的UHPC的残余应力与拉应力水平分别降低15.8%和14.7%, 其抗裂性能得到提高; 建议对粗集料UHPC进行紧密堆积设计以获得尽可能优的材性, 对掺有长度为12~20 mm钢纤维的UHPC, 其集料的最大粒径可放宽至9.5 mm。Abstract: To reduce the shrinkage and cracking risk of ultra-high-performance concrete(UHPC), the autogenerous shrinkage, basic mechanical properties(compressive strength, tensile strength and elastic modulus), aggregate gradation and restrained ring shrinkage tests on five groups UHPCs with different coarse aggregate contents(mass fractions are 0, 12.5%, 22.5%, 32.5%, and 42.5%, respectively) were studied. The influences of coarse aggregate content and aggregate gradation on the autogenerous shrinkage and basic mechanical properties of UHPC were analyzed. The proposed relative difference of shrinkage-cracking stress was used to evaluate the effect of coarse aggregate incorporation on the shrinkage-cracking of UHPC. The cracking performances of UHPCs with and without coarse aggregate under restrained ring were tested and compared. The effectiveness of coarse aggregate incorporation on reducing the shrinkage-cracking of UHPC was verified, and the suggestions for the coarse aggregate content and the maximum particle size limitation in UHPC were given. Research result shows that the autogenous shrinkage of UHPC at early age reduces with the increase of coarse aggregate content, and the maximum decreasing amplitude is about 20%. The effect degrees of coarse aggregate on the elastic modulus, compressive strength and tensile strength of UHPC are depended on its content and gradation. When the coarse aggregate content is 22.5%, the aggeregate gradation curve is almost inside the range of Fuller's and Talbot's curves. It is the most closely packed group among the five material groups. The coarse aggregate of this group has the most remarkable effect on the improvement of elastic modulus and compressive strength of UHPC, and has the minimum effect on the reduction of tensile strength. The maximum relative difference of shrinkage-cracking stress of UHPC with the coarse aggregate content of 22.5% is up to 1.31 MPa. It is the optimal content in the tests and can effectively reduce the risk of shrinkage-cracking. Comparing the UHPC without coarse aggregate, the levels of residual stress and tensile stress of UHPC with the coarse aggregate content of 22.5% under the restrained ring decreases by 15.8% and 14.7%, respectively, indicating that its crack resistance improves. The UHPC with closely packing coarse aggregate is recommended to achieve the material properties as high as possible. The maximum particle size of coarse aggregate can relaxes to 9.5 mm for the UHPC with steel fiber length of 12-20 mm.
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图 2 粗集料对UHPC自收缩的影响
Figure 2. Effect of coarse aggregate on autogenous shrinkage of UHPC
图 4 粗集料对UHPC抗压强度影响
Figure 4. Effect of coarse aggregate on compressive strength of UHPC
图 7 试件残余应力随时间发展曲线
Figure 7. Development curves of residual stresses of specimens with time
图 8 UHPC拉应力水平随时间发展曲线
Figure 8. Development curves of tensile stress levels of UHPC with time
表 1 粗、细集料粒径分布
Table 1. Particle size distributions of coarse and fine aggregates
粒径/mm 9.50 4.75 2.36 1.18 0.60 0.03 0.015 累计筛余/% 粗集料 0 86.8 99.6 细集料 0 0 44.8 57.2 91.2 98.5 
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表 2 关键龄期内UHPC的自收缩与基本力学性能指标
Table 2. Autogenous shrinkage and mechanical property indexes of UHPC at key ages
UHPC测试指标 组别 各指标随龄期(d)变化 1 3 7 14 28 60 90 自收缩/10-6 CA000 -313.3 -356.4 -452.4 -537.9 -579.3 -607.9 -615.9 CA125 -259.2 -302.7 -392.2 -485.2 -533.0 -545.7 -556.9 CA225 -264.7 -297.2 -379.7 -471.3 -520.6 -531.8 -543.5 CA325 -255.4 -288.4 -380.2 -470.6 -510.8 -510.5 -516.7 CA425 -267.0 -276.5 -364.1 -449.8 -490.8 -495.6 -496.7 抗压强度/MPa CA000 46.4 88.1 113.9 130.9 141.6 150.2 152.5 CA125 48.5 88.4 110.6 126.6 136.5 143.8 145.4 CA225 43.8 87.0 118.9 130.1 144.6 150.9 153.0 CA325 50.0 87.1 117.4 131.1 145.0 150.2 152.5 CA425 41.0 87.0 109.4 127.9 140.4 145.9 147.8 弹性模量/GPa CA000 33.5 40.1 42.1 43.4 44.4 44.9 45.1 CA125 35.6 40.8 42.9 44.2 45.3 45.4 45.9 CA225 33.7 39.6 44.6 45.9 47.2 47.5 47.8 CA325 35.7 42.2 44.3 45.9 46.9 46.9 47.0 CA425 32.9 39.7 41.9 44.0 45.3 46.4 46.9 直拉(开裂)强度/MPa CA000 8.0(7.3) CA125 7.3(7.1) CA225 7.9(7.2) CA325 6.8(6.4) CA425 5.7(5.4)
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表 3 圆环约束收缩试验参数设计
Table 3. Parameter design of restrained ring shrinkage test
UHPC组别 组别 密闭 干燥 高约束水平 低约束水平 CA225 CA225-S-L √ √ CA225-S-H √ √ CA225-D-L √ √ CA225-D-H √ √ CA000 CA000-S-L √ √ CA000-S-H √ √ CA000-D-L √ √ CA000-D-H √ √
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表 4 各龄期内UHPC自由收缩与基本力学性能指标
Table 4. Free shrinkage and mechanical property indexes of UHPC at each age
测试指标 组别 各指标随龄期(d)变化 1 2 3 7 14 28 60 90 总收缩/10-6 CA225 -291.9 -337.1 -369.9 -451.4 -510.0 -535.6 -545.7 -554.5 CA000 -408.8 -452.4 -500.9 -606.1 -680.0 -698.7 -701.9 -705.7 自收缩/10-6 CA225 -194.6 -208.9 -249.1 -362.3 -453.1 -486.0 -494.2 -496.6 CA000 -289.7 -306.1 -356.4 -489.9 -590.4 -618.7 -615.6 -619.8 抗压强度/MPa CA225 42.2 77.8 101.3 137.1 147.8 151.8 155.0 CA000 45.8 88.8 112.5 133.5 145.6 150.9 153.7 弹性模量/GPa CA225 39.0 45.8 49.4 50.7 51.8 52.0 52.2 52.6 CA000 36.3 41.8 45.0 47.0 48.1 48.9 49.5 49.7 劈裂强度/MPa CA225 11.9 13.4 15.6 16.5 16.5 16.7 17.0 CA000 11.0 12.2 13.8 15.0 15.6 16.2 16.5
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表 5 各龄期钢圆环应变
Table 5. Steel ring strains at each age
UHPC类型 组别 不同龄期(d)的钢圆环应变/10-6 1 3 7 14 28 60 90 CA225 CA225-S-L -56.6 -74.4 -128.3 -165.4 -170.3 -172.6 -173.9 CA225-S-H -31.1 -44.8 -91.7 -130.2 -134.8 -133.1 -133.5 CA225-D-L -51.8 -91.4 -129.4 -151.1 -158.9 -164.7 -160.7 CA000 CA225-D-H -38.3 -67.3 -100.4 -119.8 -120.1 -121.7 -117.1 CA000-S-L -54.0 -78.3 -134.7 -177.8 -184.3 -183.3 -184.0 CA000-S-H -23.7 -47.1 -101.5 -143.1 -145.2 -143.9 -144.7 CA000-D-L -52.4 -93.4 -143.6 -170.8 -172.3 -176.3 -173.8 CA000-D-H -27.6 -72.1 -118.8 -138.5 -137.7 -143.9 -140.2
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[1] BIRCHALL J D, HOWARD A J, KENDALL K. Flexural strength and porosity of cements[J]. Nature, 1981, 289: 388-390. doi: 10.1038/289388a0 [2] RICHARD P, CHEYREZY M. Composition of reactive powder concretes[J]. Cement and Concretce Research, 1995, 25(7): 1501-1511. doi: 10.1016/0008-8846(95)00144-2 [3] 陈宝春, 季韬, 黄卿维, 等. 超高性能混凝土研究综述[J]. 建筑科学与工程学报, 2014, 31(3): 1-24. doi: 10.3969/j.issn.1673-2049.2014.03.002CHEN Bao-chun, JI Tao, HUANG Qing-wei, et al. Review of research on ultra-high performance concrete[J]. Journal of Architecture and Civil Engineering, 2014, 31(3): 1-24. (in Chinese). doi: 10.3969/j.issn.1673-2049.2014.03.002 [4] YOO D Y, YOON Y S. A review on structural behavior, design, and application of ultra-high-performance fiber-reinforced concrete[J]. International Journal of Concrete Structures and Materials, 2016, 10(2): 125-142. doi: 10.1007/s40069-016-0143-x [5] HABERT G, DENARIÉ E, ŠAJNA A, et al. Lowering the global warming impact of bridge rehabilitations by using ultra high performance fibre reinforced concretes[J]. Cement Concrete Composites, 2013, 38: 1-11. doi: 10.1016/j.cemconcomp.2012.11.008 [6] 林上顺, 黄卿维, 陈宝春, 等. 跨海大桥U-RC组合桥墩设计[J]. 交通运输工程学报, 2017, 17(4): 55-65. doi: 10.3969/j.issn.1671-1637.2017.04.006LIN Shang-shun, HUANG Qing-wei, CHEN Bao-chun, et al. Design of U-RC composite pier of sea-crossing bridge[J]. Journal of Traffic and Transportation Engineering, 2017, 17(4): 55-65. (in Chinese). doi: 10.3969/j.issn.1671-1637.2017.04.006 [7] 程俊, 刘加平, 刘建忠, 等. 含粗骨料超高性能混凝土力学性能研究及机理分析[J]. 材料导报, 2017, 31(12): 115-119, 131. doi: 10.11896/j.issn.1005-023X.2017.012.024CHENG Jun, LIU Jia-ping, LIU Jian-zhong, et al. An experimental study and a mechanism analysis on mechanical properties of ultra-high performance concrete with coarse aggregate[J]. Materials Review, 2017, 31(12): 115-119, 131. (in Chinese). doi: 10.11896/j.issn.1005-023X.2017.012.024 [8] 马熙伦, 陈宝春, 杨艳, 等. R-UHPC梁的抗剪承载力计算方法[J]. 交通运输工程学报, 2017, 17(5): 16-26. doi: 10.3969/j.issn.1671-1637.2017.05.002MA Xi-lun, CHEN Bao-chun, YANG Yan, et al. Calculation method of shear bearing capacity of R-UHPC beam[J]. Journal of Traffic and Transportation Engineering, 2017, 17(5): 16-26. (in Chinese). doi: 10.3969/j.issn.1671-1637.2017.05.002 [9] PARK J K, PARK S H, KIM D J. Effect of matrix shrinkage on rate sensitivity of the pullout response of smooth steel fibers in ultra-high-performance concrete[J]. Cement and Concrete Composites, 2018, 94: 226-237. doi: 10.1016/j.cemconcomp.2018.09.014 [10] 黄伟, 孙伟. 石灰石粉掺量对超高性能混凝土水化演变的影响[J]. 东南大学学报(自然科学版), 2017, 47(4): 751-759. https://www.cnki.com.cn/Article/CJFDTOTAL-DNDX201704020.htmHUANG Wei, SUN Wei. Effects of limestone addition on hydration development of ultra-high performance concrete[J]. Journal of Southeast University (Natural Science Edition), 2017, 47(4): 751-759. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-DNDX201704020.htm [11] YOO D Y, PARK J J, KIM S W, et al. Influence of ring size on the restrained shrinkage behavior of ultra high performance fiber reinforced concrete[J]. Materials and Structures, 2014, 47(7): 1161-1174. doi: 10.1617/s11527-013-0119-0 [12] 陈宝春, 李聪, 黄伟, 等. 超高性能混凝土收缩综述[J]. 交通运输工程学报, 2018, 18(1): 13-28. doi: 10.3969/j.issn.1671-1637.2018.01.002CHEN Bao-chun, LI Cong, HUANG Wei, et al. Review of ultra-high performance concrete shrinkage[J]. Journal of Traffic and Transportation Engineering, 2018, 18(1): 13-28. (in Chinese). doi: 10.3969/j.issn.1671-1637.2018.01.002 [13] 张云升, 张国荣, 李司晨. 超高性能水泥基复合材料早期自收缩特性研究[J]. 建筑材料学报, 2014, 17(1): 19-23. doi: 10.3969/j.issn.1007-9629.2014.01.004ZHANG Yun-sheng, ZHANG Guo-rong, LI Si-chen. Study on early autogenous shrinkage of ultra-high performance cementitous composite[J]. Journal of Building Materials, 2014, 17(1): 19-23. (in Chinese). doi: 10.3969/j.issn.1007-9629.2014.01.004 [14] WANG Chong, YANG Chang-hui, LIU Fang, et al. Preparation of ultra-high performance concrete with common technology and materials[J]. Cement and Concrete Composites, 2012, 34(4): 538-544. doi: 10.1016/j.cemconcomp.2011.11.005 [15] 任兴涛, 周听清, 钟方平, 等. 钢纤维活性粉末混凝土的动态力学性能[J]. 爆炸与冲击, 2011, 31(5): 540-547. https://www.cnki.com.cn/Article/CJFDTOTAL-BZCJ201105016.htmREN Xing-tao, ZHOU Ting-qing, ZHONG Fang-ping, et al. Dynamic mechanical behavior of steel-fiber reactive powder concrete[J]. Explosion and Shock Waves, 2011, 31(5): 540-547. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-BZCJ201105016.htm [16] WILLE K, NAAMAN A E, PARRAMONTESINOS G J. Ultra-high performance concrete with compressive strength exceeding 150 MPa (22 ksi): a simpler way[J]. ACI Materials Journal, 2011, 108(1): 46-54. [17] 张丽辉, 刘加平, 周华新, 等. 粗骨料与钢纤维对超高性能混凝土单轴拉伸性能的影响[J]. 材料导报, 2017, 31(12): 109-114. doi: 10.11896/j.issn.1005-023X.2017.012.023ZHANG Li-hui, LIU Jia-ping, ZHOU Hua-xin, et al. Effects of coarse aggregate and steel fiber on uniaxial tensile property of ultra-high performance concrete[J]. Materials Review, 2017, 31(12): 109-114. (in Chinese). doi: 10.11896/j.issn.1005-023X.2017.012.023 [18] SCHEFFLER B, SCHMIDT M. Application of UHPC for multifunctional road pavements[C]//Kassel University Press. 3rd International Symposium on UHPC and Nanotechnology for High Performance Construction Materials. Kassel: Kassel University Press, 2012: 913-920. [19] BRIFFAUT M, BENBOUDJEMA F, TORRENTI J M, et al. A thermal active restrained shrinkage ring test to study the early age concrete behaviour of massive structures[J]. Cement and Concrete Research, 2011, 41(1): 56-63. doi: 10.1016/j.cemconres.2010.09.006 [20] 王俊颜, 边晨, 肖汝诚, 等. 常温养护型超高性能混凝土的圆环约束收缩性能[J]. 材料导报, 2017, 31(12): 52-57. doi: 10.11896/j.issn.1005-023X.2017.012.011WANG Jun-yan, BIAN Chen, XIAO Ru-cheng, et al. Restrained shrinkage behavior of ultra high performance concrete without thermal curing[J]. Materials Review, 2017, 31(12): 52-57. (in Chinese). doi: 10.11896/j.issn.1005-023X.2017.012.011 [21] 傅沛兴. 普通混凝土砂石级配的研究[J]. 建筑材料学报, 2007, 10(1): 1-6. doi: 10.3969/j.issn.1007-9629.2007.01.001FU Pei-xing. Study on the gravel-sand grading of normal class concrete[J]. Journal of Building Materials, 2007, 10(1): 1-6. (in Chinese). doi: 10.3969/j.issn.1007-9629.2007.01.001 [22] 李聪, 陈宝春, 黄卿维. 超高性能混凝土圆环约束收缩试验研究[J]. 工程力学, 2019, 36(8): 49-58. https://www.cnki.com.cn/Article/CJFDTOTAL-GCLX201908005.htmLI Cong, CHEN Bao-chun, HUANG Qing-wei. Experimental study on shrinkage of ultra-high performance concrete under restrained ring[J]. Engineering Mechanics, 2019, 36(8): 49-58. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-GCLX201908005.htm [23] 杨简, 陈宝春, 沈秀将, 等. UHPC单轴拉伸试验狗骨试件优化设计[J]. 工程力学, 2018, 35(10): 37-46, 55. https://www.cnki.com.cn/Article/CJFDTOTAL-GCLX201810005.htmYANG Jian, CHEN Bao-chun, SHEN Xiu-jiang, et al. The optimized design of dog-bones for tensile test of ultra-high performance concrete[J]. Engineering Mechanics, 2018, 35(10): 37-46, 55. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-GCLX201810005.htm [24] 王国杰. 自密实混凝土圆环约束收缩试验研究[J]. 工程力学, 2014, 31(12): 173-180. https://www.cnki.com.cn/Article/CJFDTOTAL-GCLX201412025.htmWANG Guo-jie. Experimental study on restrained shrinkage of self-compacting concrete by ring test[J]. Engineering Mechanics, 2014, 31(12): 173-180. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-GCLX201412025.htm [25] HOSSAIN A B, WEISS J. Assessing residual stress development and stress relaxation in restrained concrete ring specimens[J]. Cement and Concrete Composites, 2004, 26(5): 531-540. [26] HOSSAIN A B, WEISS J. The role of specimen geometry and boundary conditions on stress development and cracking in the restrained ring test[J]. Cement and Concrete Research, 2006, 36(1): 189-199. -
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