登录
注册
E-alert
登录
注册
E-alert
ANALYSIS OF FREEZE-THAW DETERIORATION AND DAMAGE CHARACTERISTICS OF EXISTING CRACKED CONCRETE
-
摘要: 采用预制裂缝的方法模拟实际工程中带裂缝混凝土,研究带裂缝混凝土在冻融循环条件下的损伤劣化过程及力学特性。通过对有、无预制裂缝的混凝土试件冻融循环后的表面变化观测、单轴压缩与弹性模量试验,研究冻融循环作用对有、无预制裂缝混凝土试件的弹性模量、轴心抗压强度、应力-应变关系的影响,得到了峰值应力与峰值应变随冻融循环次数的变化关系,结合损伤力学的方法分析预制裂缝对混凝土抗冻性能的影响。结果表明:无裂缝试件在冻融后出现成片剥落、边缘缺角的表面变化,而预制裂缝试件在此基础上还出现了预制裂缝沿径向扩展、侧面萌生横向裂缝的现象;预制裂缝混凝土试件强度和弹性模量的损失率更大,得到了预制裂缝试件峰值应力与冻融循环次数的计算式;裂缝使混凝土损伤率大于无预制裂缝试件。Abstract: The pre-crack method was used to simulate the cracked concrete in the actual engineering. The damage degradation process and mechanical properties of the concrete with cracks under freeze-thaw cycles were studied. Through the observation of surface change, uniaxial compression and elastic modulus test of concrete specimens with and without pre-crack to study the freeze-thaw cycles effected on the elastic modulus, axial compressive strength, stress-strain relationship of specimens with and without pre-crack, the relationship between peak stress and peak strain as a function of freeze-thaw cycles was obtained. Combined with the damage mechanics, the effects of pre-formed cracks on the frost resistance of concrete were analyzed. The results showed that, after freezing and thawing, the crack-free specimens appeared flaking of surface and corner cutted. The phenomenon of radial propagation of pre-cracks and lateral initiation of transverse cracks appeared in pre-crack specimens. The loss rate of strength and modulus of elasticity of precast cracked concrete specimens were faster. The formulas for calculating peak stress and freeze-thaw cycles of pre-crack specimens were obtained. The cracks caused the concrete damage rate to be greater than that of the specimens without pre-crack.
-
李金玉,曹建国,徐文雨,等.混凝土冻融破坏机理的研究[J].水利学报, 1999(1):42-50. WITTMANN F H, WANG P, ZHANG P, et al. Capillary Absorption and Chloride Penetration into Neat and Water Repellent SHCC Under Imposed Strain[C]//2nd Int. RILEM Conf. on Strain Hardening Cementitious Composites, Rio de Janeiro. 2011(1):165-172. CHENG Y, ZHANG Y, JIAO Y, et al. Quantitative Analysis of Concrete Property Under Effects of Crack, Freeze-Thaw and Carbonation[J]. Construction and Building Materials, 2016(129):106-115. 赵庆新,康佩佩.力学损伤对混凝土抗冻性的影响[J].建筑材料学报, 2013,16(2):326-329. WARDEH G, GHORBEL E. Prediction of Fracture Parameters and Strain-Softening Behavior of Concrete:Effect of Frost Action[J]. Materials&Structures, 2015,48(1-2):123-138. 袭杰,刁波,沈孛,等.冻融与初始裂缝对钢筋混凝土黏结强度的影响[J].混凝土, 2014(7):16-19. 于孝民,任青文.冻融循环作用下普通混凝土断裂能试验[J].河海大学学报(自然科学版), 2010(1):80-82. 宁作君,巴恒静,杨英姿.冻融环境下混凝土的断裂损伤试验研究[J].哈尔滨工程大学学报, 2009,30(1):27-32. 陈有亮,刘明亮,蒋立浩.含宏观裂纹混凝土冻融的力学性能试验研究[J].土木工程学报, 2011,44(增刊2):230-233. 王靖荣,陈有亮,傅喻.冻融环境下不同预制裂缝混凝土断裂性能研究[J].水资源与水工程学报, 2019,30(2):178-185. 余建福.裂缝对混凝土耐久性的影响研究[D].天津:河北工业大学, 2015. 逯静洲,田立宗,童立强,等.经受疲劳荷载与冻融循环作用后混凝土动态性能研究[J].应用基础与工程科学学报, 2018(5):1055-1066. 田立宗,逯静洲,朱孔峰,等.冻融循环与疲劳荷载作用下混凝土损伤研究[J].长江科学院院报, 2018,35(2):140-144. -
点击查看大图
计量
- 文章访问数: 63
- HTML全文浏览量: 6
- PDF下载量: 1
- 被引次数: 0
下载:
