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魏子程¹ , 王    林 ¹ , 贺鑫鑫¹ , 王宏波²

( 1. 北京建筑大学土木与交通工程学院 ，北京 100044 ;

2. 陕西德和建材有限公司 ，陕西 西安 710000)

摘   要： 普通喷射混凝土在喷射过程中回弹率高，粉尘量大，强度不容易达标，特别是在富水区，这些情况更为严重，在喷射混凝土中掺入一种高强超微外加剂，用来改善喷射混凝土的力学性能，降低喷射混凝土的回弹率及粉尘量。本文将高强超微外加剂应用于喷射混凝土中，研究了其对喷射混凝土力学性能及回弹率和粘结强度的影响 。试验结果表明： 高强超微外加剂能够显著提高喷射混凝土的抗压强度和抗折强度，在 C25 喷射混凝土中，高强超微外加剂掺量为 6%时，喷射混凝土 28 d 抗压强度与抗折强度与不掺高强超微外加剂组分别提高 6. 4%与 32% ; 添加高强超微外加剂的喷射混凝土在工程应用中回弹量平均只有 7. 3% , 比普通喷射混凝土 降低 28% , 粘结强度最高为 2. 29 MPa, 是普通喷射混凝土的 3 ~4 倍。

关键词： 高强超微外加剂； 喷射混凝土； 力学性能； 回弹量； 粘结强度

中图分类号： TU528. 042      

文献标志码： A      

文章编号： 1005-8249 (2023) 05-0082-06

DOI : 10. 19860/j.cnki.issn1005-8249.2023.05.014

WEI Zicheng¹ , WANG Lin¹ , HE Xinxin¹ , WANG Hongbo²

( 1. School of Civil and Transportation Engineering , Beijing University of Civil Engineering and Architecture ,

Beijing 100044 , China; 2. Shaanxi Dehe Building Materials Co. ，Ltd. ,  Xi ′an 710000 , China)

Abstract: Ordinary shotcrete in the process of spraying rebound rate is high, large amount of dust, strength is not easy to reach the standard, especially in the water-rich area, these conditions are more serious, in shotcrete mixed with a high strength ultramicro admixture, used to improve the mechanical properties of shotcrete, reduce the rebound rate of shotcrete and dust. In this paper, high strength ultramicro admixture is applied to shotcrete and its effect on mechanical properties and rebound rate of shotcrete is studied. The experimental results showed that the high-strength ultramicro admixture could significantly improve the compressive strength and flexural strength of shotcrete. In C25 shotcrete, when the dosage of high-strength ultramicro admixture was 6%, the 28d compressive strength and flexural strength of shotcrete increased by 6.4% and 32%, respectively, compared with the group without high-strength ultramicro admixture. The average rebound of shotcrete with high strength and ultra-fine admixture in engineering application is only 7.3%, 28% lower than that of ordinary shotcrete, and the highest bond strength is 2.29mpa, which is 3 ~ 4 times of that of ordinary shotcrete.

Keywords: high strength ultramicro admixture; shotcrete; mechanical properties; The springback amount; bond strength

     ∗基金项目： 市属高校基本科研业务费项目“ 轻烧氧化镁膨胀 剂在低熟料胶凝体系中的膨胀机理及稳定性研究 X18265”资助。

作者简介： 魏子程  ( 1997—) , 男 ，硕士研究生 ，主要从事 建筑材料研究。

收稿日期： 2022-08-10