改性无碱速凝剂对水泥砂浆性能影响-中国粉体技术

改性无碱速凝剂对水泥砂浆性能影响
Effect of modified alkali‑free accelerator on properties of cement mortar

丁向群，王艺潼，王妍，崔殿松

沈阳建筑大学材料科学与工程学院，辽宁沈阳 110168\

引用格式：

丁向群，王艺潼，王妍，等. 改性无碱速凝剂对水泥砂浆性能影响［J］. 中国粉体技术，2026，32（2）：1-9.

DING Xiangqun， WANG Yitong， WANG Yan， CUI Diansong. Effect of modified alkali⁃free accelerator on properties of cement mortar［J］. China Powder Science and Technology，2026，32（2）：1−9.

DOI：10.13732/j.issn.1008-5548.2026.02.016

收稿日期：2024-03-31，修回日期：2025-07-16，上线日期：2025-11-24。

基金项目：国家自然科学基金项目，编号：52378252。

第一作者：丁向群（1970—），男，教授，博士，硕士生导师，研究方向为高性能混凝土。E-mail：xiangqunding@126. com。

摘要：【目的】研究掺入硫酸盐改性无碱液体速凝剂（alkali⁃free liquid accelerator，AFA）母液对水泥砂浆力学性能及新拌砂浆与旧基材黏结性能的影响。【方法】在AFA掺量（质量分数，下同）不变的条件下，测试不同改性剂掺量下水泥砂浆的1、28 d龄期抗压强度和新拌砂浆与旧基材黏结试件的界面抗弯强度；结合水化放热分析，利用X射线衍射仪、扫描电子显微镜研究水泥水化产物及微观形貌。【结果】水泥砂浆抗压强度、界面抗弯强度均随改性剂掺量的增加呈现先增大后减小的趋势。当改性剂质量分数（掺量）为 2% 时，水泥砂浆 1、28 d龄期抗压强度分别为 17、50 MPa，与掺 8% AFA组相比，在此掺量下砂浆1 d抗压强度提升最多，28 d龄期抗压强度也略有提高，同时解决了单掺AFA导致的水泥砂浆1 d的界面抗弯强度下降的问题，并显著提高了水泥砂浆28 d龄期的界面抗弯强度。【结论】掺入改性剂，加快水泥水化放热速率，促进铝酸三钙（C₃A）与石膏（CaSO₄）反应生成大量钙矾石（ettringite， AFt），抑制了AFt向单硫型水化硫铝酸钙（AFm）转化的反应和C₃A的直接水化反应，改善水泥砂浆的孔隙结构，提高其早期强度和与旧基材的界面黏结性。

关键词：水泥；无碱液体速凝剂；改性剂；早期强度；界面抗弯强度

Abstract

Objective An accelerator is an admixture that significantly reduces the setting and hardening time of cement mortar or concrete while ensuring sufficient early strength development. Therefore， accelerators are widely used in mining， tunneling， slope sup⁃port， and emergency repair projects. Among commercially available alkali-free liquid accelerators （AFA）， aluminum sulfate is commonly used as the primary coagulant due to its high water solubility. However， Al³⁺ions tend to undergo hydrolysis， forming Al（OH）₃ colloids that can cause coagulation reactions. To enhance the stability of Al³⁺in the liquid phase， researchers generally add complexing agents such as fluorides， organic alcohol amines， or polyols. However， these agents can potentially undermine the early strength development of cement mortar. Current research on accelerator adhesiveness mainly focuses on the relationship between accelerator dosage and the rebound rate of shotcrete. Limited attention has been given to the optimized preparation of accelerators and the selection of suitable components to enhance their intrinsic adhesiveness. This paper explores the use of sulfate-based modifiers to improve the properties of AFA mother liquor. The effects of these modifiers on the early strength of cement mortar mixed with the accelerator and its bonding performance with existing substrates are evaluated， and the underlying modification mechanisms are analyzed.

Methods Different dosages （mass fraction， same below） of AFA mother liquor were added to cement mortar， and the optimal dosage was determined based on setting time. To address the issue of low early strength in the alcohol amine-aluminum sulfate system prepared by an organic-inorganic composite method， the compressive strength of cement mortar at 1 and 28 days and the interfacial flexural-tensile strength of bonded specimens at 1 and 28 days were tested under a constant accelerator dosage. The influence of sulfate modifier on the mechanical properties of cement mortar and its interfacial bonding performance with the existing substrate was also examined. To investigate the underlying mechanisms， hydration heat analysis， X-ray diffraction （XRD），and scanning electron microscopy （SEM） were conducted to study the effects of sulfate modifiers on the hydration rate， heat evolution， hydration products， and microstructure of cement at 1 day.

Results and Discussion The results indicated that the setting time of cement paste decreased with increasing dosage of AFA mother liquor. When the accelerator dosage ranged from 6% to 10%， both the initial and final setting times of cement met the national standards. Increasing the dosage from 8% to 10% further shortened the setting time， although the change was not significant. The AFA mother liquor improved the 1-day compressive strength of the cement mortar at a dosage of 8% but significantly reduced the 1-day interfacial flexural-tensile strength of the bonded specimens. The accelerator significantly enhanced the heat release rate during cement hydration， increased the two exothermic peak values， shortened the induction period， and advanced the onset of the acceleration period. The setting time， flexural strength， and compressive strength of the cement mortar and the interfacial flexural strength of the bonded specimens all initially increased and then decreased with increasing modifier content. When the modifier content was 2%， the setting time of the cement paste was minimized， and the compressive strengths of the cement mortar at 1 day and 28 days reached their maximum values， increasing by 61. 9% and 3. 6%， respectively， compared to the blank group， and increasing by 20. 3% and 3. 6%， respectively， compared to the 8% accelerator group. The 1-day interfacial flexural-tensile strength of the bonded specimens was 24. 3% higher than that of the blank group and 90. 6% higher than that of the 8% accelerator group. This improvement addressed the issue of reduced 1-day interfacial flexural-tensile strength caused by the sole addition of AFA mother liquor. The 28-day interfacial flexural-tensile strength of the bonded specimens was also significantly enhanced.

Conclusion The addition of sulfate-based modifiers further shortens the setting time of cement paste when used in combination with the accelerator， significantly enhancing the compressive strength of the cement mortar at all ages. Additionally， it addresses the issue of reduced interfacial flexural-tensile strength of the bonded specimens that occurs when only the accelerator is used. The compressive strength of the cement mortar and the interfacial flexu⁃ral strength of the bonded specimens initially increase and then decrease as the modifier c⁃ontent increases.By consuming Ca（OH)₂， the modifier promotes the reaction of C₃A， leading to the formation of coarse， needle-like ettringite （AFt） crystals that densify the cement system. This improved mor⁃phology refined the microstructure， overcoming the problem of excessively fine crystals and a loose cement structure typically caused by the accelerat⁃or alone. As a result， the overall mechanical properties of the cement mortar are improved.

Keywords：cement； alkali-free liquid accelerator； modifying agent； early strength； interfacial flexural-tensile strength

参考文献（References）

［1］陈延胜，张云，魏凯，等. 高适应性无碱液体速凝剂的制备及其应用研究［J］. 新型建筑材料，2022，49（7）：122-127.

CHEN Y S， ZHANG Y， WEI K， et al. Study on preparation and application properties of a high adaptability liquid alkalifree setting accelerator［J］. New Building Materials，2022，49（7）：122-127.

［2］ZHANG L C， JIA X N， YANG G J， et al. Research on application of high performance alkali-free liquid accelerator in shot⁃crete support［J］. MATEC Web of Conferences，2020，319：08003.

［3］GUAN M Q， LI X H， GUO X Q， et al. Study on the preparation of suspension stabilizer for liquid accelerator［J］. IOP Con⁃ference Series： Materials Science and Engineering，2020，729（1）：012105.

［4］ANGELSKAAR T. Liquid accelerator： US20070044686［P］. 2007−03−01.

［5］YANG R， HE T. The accelerating mechanism of alkali free liquid accelerator based on fluoroaluminate for shotcrete［J］.Construction and Building Materials，2021，274：121830.

［6］周博儒，王睿，高飞，等. 新型无碱液体速凝剂的制备及性能评价［J］. 新型建筑材料，2021，48（5）：29-33.

ZHOU B R， WANG R， GAO F， et al. Preparation and performance evaluation on a new type of alkali-free liquid accelera⁃tor admixture［J］. New Building Materials，2021，48（5）：29-33.

［7］WU Z， LIU J， ZHANG G， et al. Effect of aluminum sulfate alkali-free liquid accelerator with compound alkanol lamine on the hydration processes of Portland cement［J］. Construction and Building Materials，2021，308：125101.

［8］XIE H， LIU X， ZHENG Y， et al. Effect of complexation of alkanolamine in accelerators on the initial stage of cement hydra⁃tion［J］. Construction and Building Materials，2023，393：132105.

［9］CUI Y， TAN Z， ZHOU Z， et al. Preparation and application of low rebound liquid alkali-free accelerator for shotcrete［J］.

Construction and Building Materials，2023，367：130220.

［10］黄玉美，刘昭洋，田遥，等. 高粘附性低回弹无碱速凝剂及其制备方法和使用方法： CN115947564A［P］. 2023−04−11.

HUANG Y， LIU Z， TIAN Y， et al. High-adhesion low-resilience alkali-free accelerator as well as preparation method and use method thereof： CN115947564A［P］. 2023−04−11.

［11］MA Z Y， SUN Z P， TIAN J T， et al. Properties of the cement paste mixed with various types of aluminum sulfate based liquid alkali-free accelerator［J］. Key Engineering Materials，2021，876：45-50.

［12］苏美娟，王子明，赵攀，等 . 碱性和无碱液体速凝剂促凝早强作用机理对比研究［J］. 硅酸盐通报，2022，41（12）：4172-4179，4188.

SU M J， WANG Z M， ZHAO P， et al. Comparative study on mechanism of quick setting and hardening accelerating effects of alkaline and alkali-free liquid accelerators［J］. Bulletin of the Chinese Ceramic Society，2022，41（12）：4172-4179，4188.

［13］WANG Y， SHI C， LEI L， et al. Formulation of an alkali-free accelerator and its effects on hydration and mechanical properties of Portland cement［J］. Cement and Concrete Composites，2022，129：104485.

［14］WANG J H， XIE Y J， ZHONG X H， et al. Test and simulation of cement hydration degree for shotcrete with alkaline and alkali-free accelerators［J］. Cement and Concrete Composites，2020，112：103684.

［15］SALVADOR R P， CAVALARO S H P， SEGURA I， et al. Early age hydration of cement pastes with alkaline and alkali free accelerators for sprayed concrete［J］. Construction and Building Materials，2016，111：386-398.

［16］XU Y， HE T， YANG R， et al. New insights into the impact of inorganic salt on cement pastes mixed with alkali free liquid accelerator in low temperature［J］. Journal of Building Engineering，2023，70：106419.

［17］王武锁，袁倩男，宋心，等. 无碱液体速凝剂对修补砂浆性能的影响［J］. 新型建筑材料，2023，50（2）：63-65.

WANG W S， YUAN Q N， SONG X， et al. Effect of alkali-free liquid accelerator on the performance of repair mortar［J］.New Building Materials，2023，50（2）：63-65.

［18］CHEN L J， LI P C， PAN G， et al. Study on modification of alkali-free liquid accelerator of mine-used wet-mix shotcrete［J］. Advances in Materials Science and Engineering，2019，2019：3156264.

［19］NIU M， LI G， ZHANG J， et al. Preparation of alkali-free liquid accelerator based on aluminum sulfate and its accelerating mechanism on the hydration of cement pastes［J］. Construction and Building Materials，2020，253：119246.

［20］王子明，王杰，甘杰忠，等 .“水泥-速凝剂-水”系统的水化反应特征及凝结硬化机理研究现状［J］. 硅酸盐通报，2020，39（10）：3045-3054.

WANG Z M， WANG J， GAN J Z， et al. Current state of hydration reaction characteristics and setting/hardening mecha⁃nism of cement−accelerator-water system［J］. Bulletin of the Chinese Ceramic Society，2020，39（10）：3045-3054.

［21］LI G， ZHANG J， NIU M， et al. The mechanism of alkali-free liquid accelerator on the hydration of cement pastes［J］. Construction and Building Materials，2020，233：117296.

［22］LUO B， LUO Z， WANG D， et al. Influence of alkaline and alkali-free accelerators on strength， hydration and microstruc⁃ture characteristics of ultra-high performance concrete［J］. Journal of Materials Research and Technology，2021，15：3283-3295.

［23］夏忠锋，王周福，刘浩，等. 铝酸钙水泥水化产物转化过程及调控研究进展［J］. 硅酸盐学报，2022，50（12）：3323-3336.

XIA Z F， WANG Z F， LIU H， et al. Research progress on conversion process and regulation of hydrates of calcium aluminate cement［J］. Journal of the Chinese Ceramic Society，2022，50（12）：3323-3336.

［24］XU Y， HE T， MA X， et al. The influence of calcium sulphoaluminate cement on the hydration process of cement paste mixed with alkali free liquid accelerator［J］. Materials Today Communications，2022，33：104622.

改性无碱速凝剂对水泥砂浆性能影响Effect of modified alkali‑free accelerator on properties of cement mortar

改性无碱速凝剂对水泥砂浆性能影响
Effect of modified alkali‑free accelerator on properties of cement mortar