再生细骨料含水状态对砂浆性能的影响

硅酸盐通报 ›› 2022, Vol. 41 ›› Issue (9): 3036-3046.

再生细骨料含水状态对砂浆性能的影响

徐鑫¹, 张鸿儒¹, 季韬¹, 赵宝军², 姚杰²

1.福州大学土木工程学院,福州 350116;
2.中建海龙建筑科技有限公司,深圳 518110

收稿日期:2022-05-12 修回日期:2022-06-14 出版日期:2022-09-15 发布日期:2022-09-27
通讯作者: 张鸿儒,博士,副研究员。E-mail:hrzh@fzu.edu.cn
作者简介:徐鑫(1995—),男,硕士研究生。主要从事水泥基材料的研究。E-mail:1597174330@qq.com
基金资助:
国家自然科学基金(52178121);国家自然科学基金青年基金(51708119);中国建筑国际集团有限公司科技项目(CSCI-2020-Z-23);中海集团科技研发计划(COHL-2021-Z-1)

Effect of Moisture State of Recycled Fine Aggregate onProperties of Mortar

XU Xin¹, ZHANG Hongru¹, JI Tao¹, ZHAO Baojun², YAO Jie²

1. College of Civil Engineering, Fuzhou University, Fuzhou 350116, China;
2. China State Construction Hailong Technology Co., Ltd., Shenzhen 518110, China

Received:2022-05-12 Revised:2022-06-14 Online:2022-09-15 Published:2022-09-27

摘要/Abstract

摘要： 采用再生细骨料取代质量分数30%河砂制备砂浆,通过预湿处理将再生细骨料含水率处理为其饱和面干吸水率的0%、30%、70%、100%,分别控制拌合用水量或总用水量一致,研究再生细骨料含水状态对砂浆性能及微观结构的影响规律。结果表明,拌合用水量一致时,砂浆流动度随再生细骨料含水率增大而增大,骨料含水状态对养护后期(28 d)力学性能的影响较小;总用水量一致时,砂浆流动度随再生细骨料含水率增大而减小,再生细骨料干燥状态下砂浆28 d力学性能较骨料含水状态下更好。两种用水量控制方案下,采用干燥再生细骨料配制的砂浆抗氯离子侵蚀性能均表现最优,且可达到与普通砂浆相当或更优的水平。微观结果表明,骨料的含水状态对微观结构影响显著,骨料预湿处理会对使新界面过渡区孔隙率增大、平均显微硬度下降,进而对宏观力学及耐久性能产生不利影响。在工程应用中保证流动度的前提下,应尽可能采用含水率低的再生细骨料配制砂浆。

关键词: 再生细骨料, 含水状态, 砂浆, 流动度, 力学性能, 抗氯离子侵蚀, 界面过渡区

Abstract: The recycled fine aggregate (RFA) was used to replace 30% (mass fraction) of the river sand to prepare mortar. The water content of RFA was set to be 0%, 30%, 70% and 100% of the value measured under the saturated-surface-dried state, by pre-treating RFA in water. The influence of the moisture states of RFA on the properties and microstructure of mortar was experimentally investigated, by taking two types of water control methods, i.e., to keep a consistent supply of mixing water and total water, respectively. Test results show that at the given mixing water supply, the fluidity of recycled mortar increase as the water content of RFA increase, and the influence of the moisture states of aggregate on the 28 d mechanical properties is insignificant. In contrast, given a consistent total water supply. The fluidity of recycled mortar decrease as the water content of RFA increase, the mortar group prepared with the oven-dried RFA present the best 28 d mechanical properties among all the mortar groups. Besides, it is found that the resistance to chloride ion ingress of recycled mortars prepared with the oven-dried RFA is the greatest among all the mortar groups, and comparable or even higher than natural mortar counterpart, regardless of the water control methods. Test results on the micro scale show that the moisture states of RFA can influence the microstructure of mortar significantly. The pre-wetting treatment of RFA led to enlarge porosity and diminished average microhardness of the new interfacial transition zones, which thereby has a negative effect on the mechanical properties and durability of mortar on the macro scale. It is suggested that the RFA at a low water content should be used to prepare the cement mortar for practical use, given that the fluidity of mortar could be ensured.

Key words: recycled fine aggregate, moisture state, mortar, fluidity, mechanical property, resistance to chloride ion ingress, interfacial transition zone

中图分类号:

TU528

徐鑫, 张鸿儒, 季韬, 赵宝军, 姚杰. 再生细骨料含水状态对砂浆性能的影响[J]. 硅酸盐通报, 2022, 41(9): 3036-3046.

XU Xin, ZHANG Hongru, JI Tao, ZHAO Baojun, YAO Jie. Effect of Moisture State of Recycled Fine Aggregate onProperties of Mortar[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(9): 3036-3046.

参考文献

[1] KIM S W, YUN H D, PARK W S, et al. Bond strength prediction for deformed steel rebar embedded in recycled coarse aggregate concrete[J]. Materials & Design, 2015, 83: 257-269.
[2] ZHANG H R, JI T, LIU H. Performance evolution of the interfacial transition zone (ITZ) in recycled aggregate concrete under external sulfate attacks and dry-wet cycling[J]. Construction and Building Materials, 2019, 229: 116938.
[3] ZHANG H R, XU X, SU S L, et al. To improve the resistance of recycled aggregate concrete (RAC) to the internal steel corrosion by the pre-treatment of aggregate[J]. Construction and Building Materials, 2021, 306: 124911.
[4] SILVA R V, DE BRITO J, DHIR R K. Properties and composition of recycled aggregates from construction and demolition waste suitable for concrete production[J]. Construction and Building Materials, 2014, 65: 201-217.
[5] DUAN H B, YU D F, ZUO J, et al. Characterization of brominated flame retardants in construction and demolition waste components: HBCD and PBDEs[J]. Science of the Total Environment, 2016, 572: 77-85.
[6] ZHANG H R, XU X, LIU W S, et al. Influence of the moisture states of aggregate recycled from waste concrete on the performance of the prepared recycled aggregate concrete (RAC): a review[J]. Construction and Building Materials, 2022, 326: 126891.
[7] MEDINA C, ZHU W Z, HOWIND T, et al. Influence of mixed recycled aggregate on the physical-mechanical properties of recycled concrete[J]. Journal of Cleaner Production, 2014, 68: 216-225.
[8] CUENCA-MOYANO G M, MARTÍN-MORALES M, VALVERDE-PALACIOS I, et al. Influence of pre-soaked recycled fine aggregate on the properties of masonry mortar[J]. Construction and Building Materials, 2014, 70: 71-79.
[9] LE T, LE SAOUT G, GARCIA-DIAZ E, et al. Hardened behavior of mortar based on recycled aggregate: influence of saturation state at macro- and microscopic scales[J]. Construction and Building Materials, 2017, 141: 479-490.
[10] ZHAO Y X, ZENG W L, ZHANG H R. Properties of recycled aggregate concrete with different water control methods[J]. Construction and Building Materials, 2017, 152: 539-546.
[11] 张雄,黄廷皓,张永娟,等.Image-Pro Plus混凝土孔结构图像分析方法[J].建筑材料学报,2015,18(1):177-182.
ZHANG X, HUANG T H, ZHANG Y J, et al. Image-Pro Plus analysis of pore structure of concrete[J]. Journal of Building Materials, 2015, 18(1): 177-182 (in Chinese).
[12] WONG H S, HEAD M K, BUENFELD N R. Pore segmentation of cement-based materials from backscattered electron images[J]. Cement and Concrete Research, 2006, 36(6): 1083-1090.
[13] BONAKDAR A, MOBASHER B, CHAWLA N. Diffusivity and micro-hardness of blended cement materials exposed to external sulfate attack[J]. Cement and Concrete Composites, 2012, 34(1): 76-85.
[14] IGARASHI S, BENTUR A, MINDESS S. Microhardness testing of cementitious materials[J]. Advanced Cement Based Materials, 1996, 4(2): 48-57.
[15] 陈云钢,孙振平,肖建庄.再生混凝土界面结构特点及其改善措施[J].混凝土,2004(2):10-13.
CHEN Y G, SUN Z P, XIAO J Z. Charcteristics and strengthening methods of interfacial zone between aggaragate and cement paste in recyeled-aggregate concrete[J]. Concrete, 2004(2): 10-13 (in Chinese).
[16] GUERZOU T, MEBROUKI A, CASTRO-GOMES J. Study of concretes properties based on pre-saturated recycled aggregates [J]. Journal of Materials and Engineering Structures, 2018, 5(3): 279-288.
[17] 陈远远,季韬,江其东,等.再生细骨料湿度状态及掺量对混凝土工作性及抗压强度的影响[J].福州大学学报(自然科学版),2013,41(3):385-390.
CHEN Y Y, JI T, JIANG Q D, et al. Influence of the moisture states and content of recycled fine aggregate on the workability and compressive strength of concrete[J]. Journal of Fuzhou University (Natural Science Edition), 2013, 41(3): 385-390 (in Chinese).
[18] PICKEL D. Recycled concrete aggregate: influence of aggregate pre-saturation and curing conditions on the hardened properties of concrete[D]. Waterloo: University of Waterloo, 2014
[19] BRAND A S, ROESLER J R, SALAS A. Initial moisture and mixing effects on higher quality recycled coarse aggregate concrete[J]. Construction and Building Materials, 2015, 79: 83-89.
[20] BRAND A S, ROESLER J. Interfacial transition zone of cement composites with recycled concrete aggregate of different moisture states[J]. Advances in Civil Engineering Materials, 2018, 7(1): 20170090.
[21] DE OLIVEIRA M B, VAZQUEZ E. The influence of retained moisture in aggregates from recycling on the properties of new hardened concrete[J]. Waste Management, 1996, 16(1/2/3): 113-117.
[22] POON C S, SHUI Z H, LAM L. Strength of concretes prepared with natural and recycled aggregates at different moisture conditions[M]//Advances in Building Technology. Amsterdam: Elsevier, 2002: 1407-1414.