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第一期
唐先习,张景伟,孙拴虎,何 勇
摘 要:在高速公路刚构桥墩台设计与施工中,箱型薄壁墩与双薄壁墩因其施工简便,经济实用等特点而被广泛采用。本文基于ANSYS有限元软件分别对这两种结构形式进行了建模分析,以期通过对比他们的力学性能来优化设计方案,选取合理的设计参数,进一步指导施工。通过分析对比在荷载作用下最不利截面上应力和位移的变化情况,总结出同一形式薄壁墩在同一截面与不同截面下应力的变化规律,以及不同横截面积情况下桥墩顶端位移的变化规律。在考虑两种形式的薄壁墩受力性能的的基础上,给出了优化箱型薄壁墩薄壁厚度的选取范围,并针对双薄壁墩提出增加横向连接的建议。
Abstract: During the construction of rigid frame piers of expressways, box thin-walled piers and double thin-walled piers are widely used because of their lots of characteristic, such as simple construction, economy, practicality and so on. ANSYS finite element software is used to model and analyze the two types of structures, in order to optimize the design scheme by comparing their mechanical properties, and select reasonable design parameters, and guide the construction. By analyzing and comparing the changes of stress and displacement on the most dangerous cross-section under the load, the law of stress variation of the same type of thin-walled pier under the same cross-section and different cross-section are summarized. On the basis of considering the mechanical properties of two types of thin-walled piers, the thin-walled thickness of box thin-walled piers is given, and suggestions for adding the lateral connection of double thin-walled piers are put forward.
唐先习,张景伟,孙拴虎,等.基于ANSYS的薄壁墩受力性能分析及参数优化研究[J].混凝土与水泥制品,2019(1):85-90.
TANG X X,ZHANG J W,SUN S H,et al.Analysis of Mechanical Performance and Parameter Optimization of Thin-walled Pier Based on ANSYS[J].China Concrete and Cement Products,2019(1):85-90.
谭世霖,蒋雪琴,杨医博,周启源
摘 要:石场在不同的加工机械与工艺条件下得到的石屑性能差别较大,导致可在混凝土中利用的石屑数量非常有限。为了增加石屑的可利用性能,进行了石屑颗粒整形的研究。研究结果表明,对石屑进行颗粒整形,能够将不满足建设用砂要求的石屑,加工成除石粉含量略高外,其它性能均满足建设用砂要求的整形石屑。
Abstract: The properties of stone chips obtained by quarries under different processing machinery and technology conditions are quite different, which leads to the very limited number of stone chips available in concrete. In order to increase the utilization performance of stone chips, a study on the shaping of stone chips was carried out. The research results show that the granular shaping of stone chips can process the shaping stone chips which can not meet the requirements of construction sand into shaping stone chips whose properties meet the requirements of construction sand except for the slightly higher content of stone powder.
谭世霖,蒋雪琴,杨医博,等.颗粒整形对石屑性能改善的试验研究[J].混凝土与水泥制品,2019(1):91-94+100.
TAN S L,JIANG X Q,YANG Y B,et al.Experimental Research of Particle Shaping on Performance Improvement of Stone Chips[J].China Concrete and Cement Products,2019(1):91-94+100.
张卫东,王振波
摘 要:通过改变粉煤灰取代率及超掺系数,研究了粉煤灰对不同水灰比及再生混凝土粗骨料取代率透水再生混凝土力学性能的影响。结果表明,粉煤灰等量取代水泥的透水再生混凝土立方体抗压强度、抗折强度及折压比均低于基准透水再生混凝土;当粉煤灰超量取代水泥时,粉煤灰取代率低于20%时的立方体抗压强度、抗折强度及折压比均随超量系数增加而增大,但超量系数超过1.4后效果不明显;粉煤灰取代率为30%时,不同粉煤灰超量系数下力学性能均低于基准试验值;随着再生混凝土粗骨料取代率或水灰比的增大,立方体抗压强度、抗折强度及折压比均随之下降,相同水灰比或再生混凝土粗骨料取代率时,立方体抗压强度、抗折强度及折压比均随粉煤灰超量系数增大而增大,但超量系数超过1.4后效果同样不明显。
Abstract: Through changing the replacement ratio and excessive incorporation coefficient of fly ash, the effect of fly ash on the mechanical properties of the pervious recycled concrete with different W/C and the replacement ratio of recycled aggregate is studied, and the optimal replacement ratio of fly ash and excess incorporation coefficient are determined. The results show that the cubic compressive strength, flexural strength, and the ratio of flexural strength to compressive strength of pervious recycled concrete with equal amounts of fly ash to replace cement are all lower than those of normal pervious recycled concrete; when the fly ash corctent is over and the replacement ratio of fly ash is lower than 20%, the cubic compressive strength, flexural strength and the ratio of flexural strength to compressive strength increase with the increase of the excessive incorporation coefficient, but the effect is not obvious after the excessive incorporation coefficient exceeds 1.4; When the replacement ratio of fly ash is 30%, the mechanical properties of different fly ash exceesive incorporation coefficients are lower than the benchmark value, so it is recommended that the replacement ratio of fly ash should not exceed 20%. With the increase of the replacement ratio of recycled concrete aggregates or the W/C, the cubic compressive strength, flexural strength and the ratio of flexural strength to compressive strength all decrease. Under the same W/C or the replacement ratio of recycled concrete aggregates, the cubic compressive strength, flexural strength, and the ratio of flexural strength to compressive strength all increase with the increase of the fly ash excessive incorporation coefficient, but the effect is not also obvious after the excessive incorporation coefficient exceeds 1.4.
张卫东,王振波.粉煤灰改性透水再生混凝土力学性能试验研究[J].混凝土与水泥制品,2019(1):95-100.
ZHANG W D,WANG Z B.Experimental Study on Mechanical Properties of Pervious Recycled Concrete Modified by Fly Ash[J].China Concrete and Cement Products,2019(1):95-100.
摘 要:针对目前砌筑砂浆强度检测领域采用的技术方法及研究现状进行分析,总结和比较了不同检测技术方法的优缺点,探讨了砌筑砂浆抗压强度检测技术方法的研究发展。研究结果表明,应根据不同的工程情况,选择不同的检测方法,以便更准确地推定砌筑砂浆抗压强度、更好地为工程质量控制服务,同时确保结构的安全。
Abstract: In view of the present method and the adopted technology of the masonry mortar strength testing field research status are analyzed, the advantages and disadvantages of different detection methods are summarized and compared, the masonry mortar compressive strength testing technology and methods of research and development are discussed. The results show that different detection methods should be selected according to different engineering conditions, so that more accurate presumption of compressive strength of masonry mortar can better service for the engineering quality control, which can ensure the structure safety.
侯高峰.砌筑砂浆抗压强度现场检测技术方法研究[J].混凝土与水泥制品,2019(1):79-84.
HOU G F.Research of Field Testing Technology on Compressive Strength of Masonry Mortar[J].China Concrete and Cement Products,2019(1):79-84.
吴渝玲,马建斌
摘 要:基于扩展有限元方法,模拟不同缝高比以及截面高度混凝土三点弯曲梁断裂破坏过程,构建了混凝土梁荷载-开口位移的数学模型,研究初始缝高比及构件尺寸对混凝土梁应力强度因子以及损伤耗能的影响发展规律。研究结果表明,混凝土梁三点弯曲的荷载-开口位移发展曲线可以分为线性上升、非线性上升与非线性下降三个阶段。混凝土梁抵抗断裂破坏的能力会随着初始缝高比的增大而减小,随着构件截面高度的增大而增强。相同荷载下混凝土应力强度因子会随着初始缝高比的增大而增大,随着截面高度的增大而减小。混凝土梁构件三点弯曲加载过程中的损伤耗能具有明显的三阶段发展演化规律。
Abstract: The simulation of different seam height ratio and section height of concrete beam fracture failure process under three point bending stress was carried out based on extended finite element method. The mathematical model of the concrete beam load-opening displacement was built. The influence of the initial size seam high ratio and component size on the stress intensity factor of concrete beam and the damage energy dissipation law of development was studide. The results show that the load and opening displacement curve of concrete beams under three point bending stress can be divided into linear ascend, nonlinear ascend and non-linear decline in three stages. The concrete beam fracture damage resistance decreases with the increase of initial seam height ratio and enhances with the increase of component section height. The stress intensity factor of concrete will increase with the increase of initial seam height ratio and decrease with the increase of section height under the same load. The damage energy consumption of concrete beam component under three-point bending loading has obvious three-stage evolution regularity.
吴渝玲,马建斌.基于扩展有限元的混凝土梁断裂破坏仿真研究[J].混凝土与水泥制品,2019(1):73-78.
WU Y L,MA J B.Study on Simulation of Fracture Failure of Concrete Beams Based on Extended Finite Element[J].China Concrete and Cement Products,2019(1):73-78.
摘 要:将废弃发泡水泥加工成轻骨料,掺入发泡水泥浆中制备轻骨料泡沫混凝土,测试其干密度、抗压强度、比强度、软化系数、导热系数和质量吸水率等性能。结果表明,干密度随着轻骨料掺量的增加先增加后减少,抗压强度、比强度、软化系数和导热系数均随着轻骨料掺量的增加而减少,质量吸水率则随着轻骨料掺量的增加而增加。当废弃发泡水泥轻骨料的掺量为60kg/m3时,轻骨料泡沫混凝土比强度高、导热系数小、软化系数高,综合性能优异。Abstract:Thewastefoamedcementisprocessedintolightaggregateandmixedintofoamedcementslurrytopreparelightweightaggregatefoamconcrete,anditsdrydensity,compressivestrength,specificstrength,softeningcoefficient,thermalconductivityandmasswaterabsorptionratearetested.Theresultsshowthatthedrydensityincreasesfirstandthendecreaseswiththeincreaseoflightaggregatecontent.Thecompressivestrength,specificstrength,softeningcoefficientandthermalconductivitydecreasewiththeincreaseoflightaggregatecontent,andthemasswaterabsorptionrateincreaseswiththeincreaseintheamountoflightaggregateincreases,andtheinterfacebetweenthefoamedcementslurryandthewastefoamedcementlightweightaggregateisgood.Whenthedosageofwastefoamedcementlightaggregateis60 kg/m3,thelightweightaggregatefoamconcretehashighspecificstrength,smallthermalconductivity,highsofteningcoefficientandexcellentcomprehensiveperformance.
黄芳美,薛力梨,刘红飞,等.用废弃发泡水泥制备轻骨料泡沫混凝土的研究[J].混凝土与水泥制品,2019(1):69-72.
HUANG F M,XUE L L,LIU H F,et al.Research on Lightweight Aggregate Foam Concrete Prepared by Waste Foamed Cement[J].China Concrete and Cement Products,2019(1):69-72.