摘要
研究目的:抗弯拉强度是碾压混凝土基层(RCC)的材料设计与施工质量控制关键指标,由于碾压混凝土材料组成及施工工艺与水泥混凝土等存在明显差异,现有抗弯拉强度换算公式是否适宜于碾压混凝土有待进一步验证。本文通过室内无侧限抗压强度(f_(c))和抗弯拉强度(f_(f))试验,分析室内标准养护、现场洒水养护以及养护不当条件下的碾压混凝土抗弯拉与抗压强度发展规律,探究两者之间的定量相关关系,并建立适宜于RCC基层的抗弯拉强度和抗压强度换算模型。研究结论:(1)现有规范推荐的水泥混凝土抗弯拉强度预估模型不适宜于碾压混凝土,其显著低估了碾压混凝土的抗弯拉能力;(2)养护条件对RCC早期强度形成及长期强度发展影响极为显著:养护不当条件下,1d抗弯拉强度仅为标准养护的50%,28d抗弯拉强度和抗压强度分别约为标准养护的82%和66%;早期充分保湿养护对保障RCC基层最终强度与耐久性至关重要;(3)与碎石混凝土、卵石混凝土及普通水泥混凝土相比,RCC具有更大的折压比;(4)本文研究成果可应用在道路路面基层工程领域,为碾压混凝土基层材料设计与施工过程质量控制提供参考。
Research purposes:Flexural tensile strength is a critical parameter for the material design and construction quality control of RCC base layers.Owing to the distinct differences in material composition and construction techniques between RCC and conventional cement concrete,the applicability of existing empirical formulas for converting compressive strength to flexural strength requires further validation for RCC.This study investigates the development of compressive strength(fc)and flexural tensile strength(ff)of RCC through laboratory experiments under three different curing conditions:standard laboratory curing,on-site water spraying,and inadequate curing.The relationship between compressive and flexural strength is quantitatively analyzed,and a conversion model tailored to RCC base layers is proposed.Research conclusions:(1)Existing flexural strength models for cement concrete are unsuitable for RCC,as they significantly underestimate its flexural capacity.(2)Curing has a major impact on strength development.Improper curing reduces 1-day flexural strength to 50%,and 28-day flexural and compressive strengths to 82% and 66% of standard curing,respectively.(3)RCC shows a higher flexural-to-compressive strength ratio than crushed stone,pebble,and conventional concretes.(4)The research results are mainly applied in the field of road basement engineering,providing a basis for strength prediction,material design,and quality control in the construction of RCC pavement base structures.
作者
张清峰
艾长发
ZHANG Qingfeng;AI Changfa(China Railway Siyuan Survey and Design Group Co.Ltd,Wuhan,Hubei 430063,China;Southwest Jiaotong University,Chengdu,Sichuan 610031,China)
出处
《铁道工程学报》
北大核心
2025年第8期21-25,共5页
Journal of Railway Engineering Society
基金
高温多雨地区特重交通城市快速路碾压混凝土基层抗裂技术(院科2018K111)。
关键词
碾压混凝土基层
抗弯拉强度预估
养护条件
相关性
roller compacted concrete base
flexural tensile strength prediction
curing conditions
correlation
作者简介
张清峰,1979年出生,男,正高级工程师;艾长发,1975年出生,男,教授。
