Direct shear mechanical properties and damage evolution of coral seawater sea-sand concrete after high temperature
-
摘要:
在远海岛礁建设中，珊瑚海水海砂混凝土(CSSC)中的珊瑚、海砂、海水可就地取材，有效解决了施工过程中混凝土骨料运输成本高、工期难以保证等问题，CSSC投入使用为我国滨海建设取材提供了新方向。但珊瑚骨料存在疏松多孔、内部孔隙结构复杂、吸水率高等缺点，导致其制作而成的珊瑚混凝土强度低、脆性大、抗高温性能差，这严重阻碍了它在一些重要结构构件中的应用。本文通过将珊瑚粗骨料、海砂、海水与水泥结合，制备了CSSC，观察了CSSC高温后的表面特征及剪切破坏形态，分析了不同温度后CSSC的剪切应力-位移曲线及垂直位移-剪切位移曲线，如 图1 、图2 所示。根据试验结果，探究了不同经历温度及不同恒温时长对CSSC剪切应力、体积膨胀率、质量损失率等的影响规律，如图3 ，建立了高温后CSSC剪切强度计算方程。结果表明：800℃时剪切应力仅为常温的39%；体积膨胀率、质量损失率分别为7%、12%。最后，基于普通混凝土高温后损伤本构模型，建立了高温后CSSC损伤演化及直剪荷载-位移全曲线模型。不同经历温度下CSSC应力-位移曲线Stress-displacement curves of CSSC under different high temperatures 不同经历温度下CSSC垂直位移-剪切位移曲线Vertical displacement-shear displacement curves of CSSC under different high temperatures 不同经历温度对CSSC剪切应力及体积膨胀率的影响Effects of different high temperatures on CSSC's volume expansion and shear stress Abstract: In order to explore the direct shear mechanical properties and constitutive relationship of coral seawater sea-sand concrete (CSSC) after high temperature, the direct shear test of CSSC after high temperature was designed and completed with maximum high temperature T and constant temperature duration H as changing parameters. The failure mode and stress-displacement curve of CSSC under direct shear were observed, and the effects of maximum high temperature T and constant high temperature duration H on the shear strength, volume expansion and mass loss of CSSC were obtained. Then the damage evolution process of CSSC after high temperature was analyzed and compared. The results show that the high temperature leads to non-uniform temperature fields, surface cracks and corner cracks in CSSC. With the increase of maximum high temperature and constant high temperature duration, the shear strength of CSSC decreases gradually while the volume expansion rate and the mass loss rate gradually increase. When T>400℃, the decrease rate of shear strength accelerates. When T=800℃, the direct shear strength of CSSC is only 39% of that at room temperature. Finally, the direct shear strength calculation equation of CSSC after high temperature and its damage constitutive model are proposed. -
图 3 不同经历温度下CSSC直剪典型破坏形态
Figure 3. Direct shear typical failure patterns of CSSC under different high temperatures
图 4 高温后CSSC直剪应力-位移曲线
Figure 4. Direct shear stress-displacement curves of CSSC under high temperatures
图 5 不同经历温度下CSSC垂直位移-剪切位移曲线
Figure 5. Vertical displacement-shear displacement curves of CSSC under different high temperatures
图 6 经历温度对CSSC剪切应力及体积膨胀率的影响
Figure 6. Effects of different high temperatures on CSSC's volume expansion and shear stress
图 8 400℃恒温时长对CSSC剪应力及体积膨胀率的影响
Figure 8. Effects of 400℃ constant temperature duration on CSSC's shear stress and volume expansion
图 9 400℃恒温时长对CSSC质量损失的影响
Figure 9. Effect of 400℃ constant temperature duration on CSSC's mass loss
图 11 高温后CSSC直剪实测曲线-理论曲线对照
Figure 11. Direct shear test curve-theoretical curve control curves of CSSC under different high temperatures
表 1 珊瑚粗骨料物理性能
Table 1. Physical properties of coral coarse aggregate
Property Water absorption/% Moisture content/% Bulk density/(kg·m−3) Apparent density/(kg·m−3) Value 12.79 0.67 879.90 1667.00 Note：CA—Coral coarse aggregate. 
下载: 导出CSV
表 2 珊瑚海水海砂混凝土(CSSC)试验设计及其抗压强度
Table 2. Test design and compressive strength of coral seawater sea-sand concrete (CSSC)
Number T / ℃ H / h fcuT / MPa Number T / ℃ H / h fcuT / MPa T25 25 — 30.43 T400-H3 400 3 22.12 T200-H1 200 1 27.08 T500-H1 500 1 19.57 T300-H1 300 1 26.66 T600-H1 600 1 14.38 T400-H1 400 1 22.38 T700-H1 700 1 10.47 T400-H2 400 2 23.94 T800-H1 800 1 8.93 Notes：fcuT is the cubic compressive strength of coral seawater sand concrete after high temperature; T is the high temperature; H is the constant high temperature duration.
下载: 导出CSV
表 3 珊瑚海水海砂混凝土配合比
Table 3. Coral seawater sea-sand concrete mix ratio
kg/m3 W/C Coral Sea-sand Cement Seawater Additional Seawater Water reducing Coral seawater sea-sand concrete 0.4 655.8 760.1 535.0 214.0 75.1 1.4 Note：W/C is the water-cement ratio of coral seawater sand concrete.
下载: 导出CSV
表 4 高温后CSSC直剪强度数据对照
Table 4. Comparison of CSSC direct shear strength data after high temperature
T /℃ fcuT/MPa τ1/MPa τ2/MPa τ3/MPa τA/MPa Standard deviation Variance Coefficient of variation τΤ/MPa τA/τΤ 200 27.08 3.66 2.94 3.13 3.24 0.37 0.14 0.12 3.27 0.99 300 26.66 2.69 2.96 3.23 2.96 0.27 0.07 0.09 3.12 0.95 400 22.38 2.99 2.47 2.74 2.73 0.26 0.07 0.10 2.84 0.96 500 19.57 2.12 1.71 2.52 2.12 0.41 0.16 0.19 2.38 0.89 600 14.38 1.65 1.49 1.78 1.64 0.15 0.02 0.09 1.83 0.90 700 10.47 1.51 1.08 1.48 1.36 0.24 0.06 0.18 1.32 1.03 800 8.93 1.03 1.13 — 1.08 0.07 0.01 0.07 0.92 1.17 Notes：τ1、τ2、τ3 are the shear test values of CSSC after high temperature; τA is the mean shear test value of CSSC after high temperature; τΤ is the mean shear theory value of CSSC after high temperature.
下载: 导出CSV
-
[1] 柴源, 牛勇, 李文杰, 等. 珊瑚骨料混凝土改性技术研究进展[J]. 材料导报, 2021, 35(15):15134-15142. doi: 10.11896/cldb.19100116CHAI Y, NIU Y, Li W J, et al. Research Progress on Improved Technology of Coral Aggregate Concrete[J]. Materials Reports,2021,35(15):15134-15142(in Chinese). doi: 10.11896/cldb.19100116 [2] 李小伟, 曹旗. FRP配筋海水珊瑚骨料混凝土材料及构件力学性能研究进展[J]. 复合材料学报, 2022, 39(3):926-941. doi: 10.13801/j.cnki.fhclxb.20210902.004LI X W, CAO Q. Research progress on mechanical properties of FRP reinforced seawater coral aggregate concrete materials and structural components[J]. Acta Materiae Compositae Sinica,2022,39(3):926-941(in Chinese). doi: 10.13801/j.cnki.fhclxb.20210902.004 [3] DA B, CHEN Y, YU H F, et al. Preparation technology, mechanical properties and durability of coral aggregate seawater concrete in the island-reef environment[J]. Journal of Cleaner Production,2022,339:130572. doi: 10.1016/j.jclepro.2022.130572 [4] XIAO J Z, QIANG C B, Antonio Nanni, et al. Use of sea-sand and seawater in concrete construction: Current status and future opportunities[J]. Construction and Building Materials,2017,155:1101-1111. doi: 10.1016/j.conbuildmat.2017.08.130 [5] HANG Y J, LI X W, LU Y, et al. Effect of mix component on the mechanical properties of coral concrete under axial compression[J]. Construction and Building Materials, 2019, 223 736–754. [6] MA L J, LI Z, Liu J G, et al. Mechanical properties of coral concrete subjected to uniaxial dynamic compression[J]. Construction and Building Materials,2019,199:244-255. doi: 10.1016/j.conbuildmat.2018.12.032 [7] R. A. Arumugam, K. Ramamurthy. Study of compressive strength characteristics of coral aggregate concrete[J]. Magazine of Concrete Research,1996,48(176):141-148. doi: 10.1680/macr.1996.48.176.141 [8] XIE Q H, XIAO J Z, ZONG Z L. Strength and microstructure of seawater and sea sand mortar after exposure to elevated temperatures[J]. Construction and Building Materials,2022,322:126451. doi: 10.1016/j.conbuildmat.2022.126451 [9] LYU Bangcheng, WANG A G, ZHANG Z H, et al. Coral aggregate concrete: Numerical description of physical, chemical and morphological properties of coral aggregate[J]. Cement & Concrete Composites,2019,100:25-34. [10] 李雨珊, 尹世平, 刘运超. FRP筋与全珊瑚骨料海水混凝土界面粘结-滑移本构关系[J/OL]. 复合材料学报: 1-16. DOI: 10.13801/j.cnki.fhclxb.20210927.004.LI Y S, YIN S P, LIU Y C. Bond-slip constitutive relation between FRP bars and coral aggregate seawater concrete[J/OL]. Acta Materiae Compositae Sinica, : 1- 16 (in Chinese). [11] HUANG Y J, HE X J, SUN H S, et al. Effects of coral, recycled and natural coarse aggregates on the mechanical properties of concrete[J]. Construction and Building Materials,2018,192:330-347. doi: 10.1016/j.conbuildmat.2018.10.111 [12] WU Z Y, ZHANG J H, YU H F, et al. 3 D mesoscopic analysis on the compressive behavior of coral aggregate concrete accounting for coarse aggregate volume and maximum aggregate size[J]. Composite Structures,2021,273:114271. doi: 10.1016/j.compstruct.2021.114271 [13] YAO W J, PANG J Y, LIU Y S. Performance degradation and microscopic analysis of lightweight aggregate concrete after exposure to high temperature [J]. Materials 2020, 13 (07): 1566. [14] 王怀亮, 朱建威. 高性能轻骨料混凝土高温后受压本构关系研究[J]. 建筑结构学报, 2019, 40(11):200-209.WANG H L, ZHU J W. Compressive behaviour of high performance lightweight concrete after high temperature[J]. Journal of Building Structures,2019,40(11):200-209(in Chinese). [15] 周春恒, 王君义, 王新堂, 等. 高温作用后GFRP筋与海水珊瑚混凝土粘结性能试验研究[J/OL]. 复合材料学报: 1-14. DOI: 10.13801/j.cnki.fhclxb.20220623.001.ZHOU C H, WANG J Y, WANG X T, et al. Experimental study on bond behavior of GFRP bar and seawater coral aggregate concrete after exposure to high temperatures[J/OL]. Acta Materiae Compositae Sinica, 1-14 (in Chinese). [16] 余振鹏, 黄侨, 谢兴华, 等. 普通与轻集料砼压-剪复合受力性能试验研究[J]. 材料导报, 2018, 32(24):4269-4275. doi: 10.11896/j.issn.1005-023X.2018.24.011YU Z P, HUANG Q, XIE X H, et al. Comparative Study on Compressive-Shear Behavior of Ordinary Concrete and Lightweight Aggregate Concrete[J]. Materials Reports,2018,32(24):4269-4275(in Chinese). doi: 10.11896/j.issn.1005-023X.2018.24.011 [17] 李志卫, 肖建庄, 孙振平. 高温后高强混凝土剪切强度与细观结构[J]. 建筑材料学报, 2015, 18(6):953-957. doi: 10.3969/j.issn.1007-9629.2015.06.007LI Z W, XIAO J Z, SUN Z P. Shear Strength and Meso-structure of High Strength Concrete after Elevated Temperatures[J]. Journal of Building Materials,2015,18(6):953-957(in Chinese). doi: 10.3969/j.issn.1007-9629.2015.06.007 [18] 陈宗平, 戴上秦, 王成, 等. 栓钉连接件、锚固及降温方式对高温喷水后型钢再生混凝土界面剪力传递的影响[J]. 防灾减灾工程学报, 2022, 42(2):362-371.CHEN Z P, DAI S Q, WANG C, et al. Effect of Stud Connector, Anchorage and Cooling Method on Interfacial Shear Transfer of Steel Reinforced Recycled Concrete after High Temperature Water Spraying[J]. Journal of Disaster Prevention and Mitigation Engineering,2022,42(2):362-371(in Chinese). [19] 冯峥, 李传习, 周佳乐, 等. UHPC键齿湿接缝直剪试验及湿接缝直剪承载力统一公式[J]. 土木工程学报, 2022, 55(6):79-91.FENG Z, LI C X, ZHOU J L, et al. Direct shear test on UHPC key-wet-joints and the unified calculation formula of direct shear capacity of UHPC wet-joints[J]. China Civil Engineering Journal,2022,55(6):79-91(in Chinese). [20] R. C[J]. K. Wong, S. K. Y. Ma, R. H. C. Wong, et al. Shear strength components of concrete under direct shearing, Cement and Concrete Research,2007,37(8):1248-1256. [21] 陈宇良, 姜锐, 陈宗平, 等. 直剪状态下再生混凝土的变形性能及损伤分析[J]. 材料导报, 2021, 35(19):19015-19021. doi: 10.11896/cldb.20090047CHEN Y L, JIANG R, CHEN Z P, et al. Deformation Performance and Damage Analysis of Recycled Concrete Under Direct Shear Condition[J]. Materials Reports,2021,35(19):19015-19021(in Chinese). doi: 10.11896/cldb.20090047 [22] 中国国家标准化管理委员会. 轻集料及其试验方法, 第2部分: 轻集料试验方法: GB/T 17431.1-2010[S]. 中国标准出版社, 2010.Standardization Administration of the People's Republic of China. Lightweight aggregates and its test methods—Part 2: Test methods for lightweight aggregates: GB/T 17431.1-2010[S]. China Quality and Standards Publishing & Media Co. , Ltd, 2010 (in Chinese). [23] 中华人民共和国住房和城乡建设部. 轻骨料混凝土应用技术标准: JGJ/T12-2019[S]. 北京: 中国建筑工业出版社, 2019.Ministry of Housing and Urban-Rural Development of the People's Republic of China. Technical standard for application of lightweight aggregate concrete: JGJ/T12-2019[S]. Beijing: China Architecture & Building Press, 2019 (in Chinese). [24] 中国工程建设标准化协会. 珊瑚骨料混凝土应用技术规程: T/CECS 694-2020[S]. 中国计划出版社, 2020.China Association for Engineering Construction Standardization. Technical specification for coral aggregate concrete: T/CECS 694-2020[S]. China Planning Press, 2020 (in Chinese). [25] XIAO J Z, LI Z W, XIE Q H, et al. Effect of strain rate on compressive behaviour of high-strength concrete after exposure to elevated temperatures[J]. Fire Safety Journal,2016:83. [26] 过镇海, 时旭东. 钢筋混凝土的高温性能及其计算[M]. 清华大学出版社, 2003.GUO Z H, SHI X D. High Temperature Performance and Calculation of Reinforced Concrete[M]. Tsinghua University Press, 2003 (in Chinese). [27] 肖洋, 彭刚, 黄超, 等. 压剪共同作用下混凝土的损伤演化研究[J]. 水利水运工程学报, 2018(2):112-119.XIAO Y, PENG G, HUANG C, et al. Damage evolution study of concrete under joint action of compression and shear[J]. Hydro-Science and Engineering,2018(2):112-119(in Chinese). -
下载:
点击查看大图
计量
- 文章访问数: 150
- HTML全文浏览量: 163
- PDF下载量: 3
- 被引次数: 0
