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(1 山西工程科技職業(yè)大學發(fā)展規(guī)劃部, 晉中 030619; 2 山西六建集團有限公司, 太原 030024;3 呼和浩特職業(yè)學院建筑工程學院, 呼和浩特 010020; 4 內蒙古農業(yè)大學水利與土木建筑工程學院, 呼和浩特 010018)
摘要: 為研究珊瑚砂摻量對超高性能混凝土(UHPC)的抗壓、抗折力學性能及干濕循環(huán)耐久性的影響,用珊瑚砂取代石英砂制備成 UHPC,替代率分別為 0%、20%、40%、60%、80%、100%,研究了不同珊瑚砂摻量的 UHPC 的抗壓、抗折和抗硫酸鹽干濕循環(huán)能力. 結果表明:在標準養(yǎng)護 28d 后,摻入 100% 的珊瑚砂 UHPC 的抗壓強度為108. 9MPa,抗折強度為 37. 7MPa,珊瑚砂由于其吸水性強的特點會抑制 UHPC 早期抗壓強度(28d 前)的發(fā)展,抗折強度變化率高于抗壓強度;隨著硫酸鈉干濕循環(huán)次數的增加,UHPC 抗壓強度逐漸增加,珊瑚砂摻量與抗壓強度差值之間存在較好的相關性;干濕循環(huán) 15 次時,UHPC 基體中水泥砂漿結構更加疏松多孔,孔隙直徑較大,水化產物晶體數量少,而干濕循環(huán) 60 次時,珊瑚砂摻量為 100%的 UHPC 組的掃描電鏡中鈣礬石晶體發(fā)育狀態(tài)良好,其結構尺寸較小且極為纖細.
關鍵詞: 珊瑚砂; 超高性能混凝土; 抗壓強度; 抗折強度; 干濕循環(huán); 耐久性
中圖分類號:TU528 文獻標志碼:A 文章編號:1002-848X(2023)10-0082-04
DOI:10. 19701 / j. jzjg. 20211563
Study on influence of coral sand content on mechanics and dry-wet cycle durability of ultra-high performance concrete
WEN Yuanyuan1, GONG Yongsheng2, REN Rong3, YAN Jianwen4
(1 Development Planning Department of Shanxi Vocational University of Engineering and Technology, Jinzhong 030619,China; 2 Shanxi Sixth Construction Co. , Ltd. , Taiyuan 030024, China; 3 Architecture and Engineering College,Hohhot Vocational College, Hohhot 010020, China; 4 Water Conservancy and Civil Engineering College, InnerMongolia Agricultural University, Hohhot 010080, China)
Abstract: In order to study the influences of compressive, flexural mechanical properties and dry-wet cycle durability ofcoral sand content to ultra-high performance concrete (UHPC), coral sand was used to replace quartz sand to prepareUHPC, and the substitution rate was 0%, 20%, 40%, 60%, 80% and 100% respectively to study the compressive,flexural and sulfate dry-wet cycle resistance of UHPC with different coral sand contents. The results show that after 28 daysof standard curing, the compressive strength of UHPC mixed with 100% coral sand is 108. 9 MPa, and the flexural strengthis 37. 7 MPa. Because of its strong water absorption, coral sand can inhibit the development of early compressive strength ofUHPC (before 28d), and the change rate of flexural strength is higher than that of compressive strength. The compressivestrength of UHPC increased gradually with the increase of dry-wet cycles of sodium sulfate, and there is a good correlationbetween the content of coral sand and the difference of compressive strength. When the dry-wet cycles are 15 times, thestructure of cement mortar in the UHPC matrix is more loose and porous, the pore diameter is larger, and the number ofhydration product crystals is less. However, when the dry-wet cycles are 60 times, the crystal of ettringite in the UHPCgroup with 100% coral sand content is in a good state, and its structure size is small and extremely slim.
Keywords:coral sand; ultra-high performance concrete (UHPC); compressive strength; flexural strength; wet-dry cycle;durability
∗山西省教育廳職業(yè)院校教師素質提高計劃國家級培訓項目(ZDF03-FC190901_2).
第一作者:溫媛媛,碩士,副教授,主要從事建筑技術科學、建筑結構方面研究,Email:daynight9999@ outlook. com.
[引用本文] 溫媛媛,弓永勝,任蓉,等. 珊瑚砂摻量對超高性能混凝土力學及干濕循環(huán)耐久性的影響研究[J]. 建筑結構,2023,53(8):82-85,81. WEN Yuanyuan,GONG Yongsheng,REN Rong,et al. Study on influence of coral sand content onmechanics and dry-wet cycle durability of ultra-high performance concrete[J]. Building Structure,2023,53(8):82-85,81.
