高强钢纤维泵送混凝土的试验及应用

结合京沪高速公路南运河大桥C50钢纤维泵送混凝土的施工,阐述了高强钢纤维泵送混凝土的原材料选择、配合比设计、混凝土的配制以及在施工应用中取得的效果。     

C50 钢纤维泵送混凝土配合比试验研究及工程应用

以泸州市沱江四桥及连接线工程跨江大桥C50钢纤维泵送混凝土配合比设计为例,采用泸州地区当地生产的原材料配制C50钢纤维泵送混凝土,介绍了C50钢纤维泵送混凝土的配合比设计试验过程,并对该混凝土施工性能和力学性能进行了试验研究,确定了符合设计和施工要求的混凝土配合比。     

高强钢纤维泵送混凝土的试验及应用

结合京沪高速公路南运河大桥C50钢纤维泵送混凝土的施工,阐述了高强钢纤维泵送混凝土的原材料选择、配合比设计、混凝土的配制以及在施工应用中取得的效果.     

珊溪工程抗冲磨高性能泵送钢纤维混凝土的研究和应用

本文介绍了珊溪水利工程用抗冲磨高性能泵送钢纤维混凝土的研究和应用,内容包括:不同强度、不同钢纤维掺量对钢纤维混凝土各项物理力学性能及抗冲磨性能的影响;C40硅粉钢纤维混凝土的各项性能研究以及现场工程应用取样结果.     

准朔黄河特大桥大掺量钢纤维混凝土顶升施工技术

准朔铁路黄河特大桥主桥设计为1-380m上承式提篮拱结构,提篮拱由8根钢管组成,内需填充高性能混凝土和钢纤维混凝土以加强钢管的刚度和整体稳定性,传统的钢纤维混凝土施工技术很难满足顶升要求。重点介绍了泵送大掺量钢纤维混凝土的研制、施工生产以及钢纤维混凝土顶升等施工工艺,并通过模拟试验对顶升质量进行了研究,取得了较好的效果。     

不同种类钢纤维在C30泵送混凝土中的应用试验研究

为探讨不同种类钢纤维及掺量对C30泵送混凝土工作性能及力学性能的影响,主要研究了钢纤维混凝土工作性能、抗压强度及弯曲韧性。研究表明:钢纤维的掺入会影响混凝土泵送施工性能,经配合比优化后剪切压痕型和哑铃型钢纤维混凝土泵送性能优良;同掺量钢纤维混凝土,峰值前韧度差异相对较小,不同类型钢纤维的增韧效果主要体现在峰值后韧度的提高上,其中端钩型效果最好,其次为高强微细平直型,哑铃型和剪切压痕型峰值后韧度相当;对于低强度等级C30泵送混凝土,钢纤维增韧效果的发挥不仅与钢纤维自身强度有关,同时与钢纤维异性化程度和掺量有关。     

钢纤维混凝土在西直门立交点支承异型板桥的施工

钢纤维混凝土具有良好的抗弯韧性、抗裂及抗冲切等性能。本文论述西直门立交的点支承预应力混凝土异型板结构，采用钢纤维混凝土提高板的抗冲切承载力的施工方法。按《规程》CECS38：92，并结合工程的实际情况进行施工。在施工中使用混凝土泵进行泵送浇筑，在北京市还是首次。     

补偿收缩级配钢纤维混凝土配制及其在钢管拱泵送顶升工程中的应用

结合准朔铁路黄河特大桥钢管拱顶升钢纤维混凝土施工,以整体论思想为设计理念,通过大量试验,归纳总结出用于泵送顶升工艺施工的混杂钢纤维混凝土配合比设计方法,所设计出的混凝土具有大流动性且保持时间长、延后初凝并早强、可补偿收缩等性能,解决了大跨度钢管拱桥混凝土泵送顶升工艺施工难题。     

泵送钢纤维混凝土配合比设计与应用

以天津东站交通枢纽工程五经路地道工程隧道路面铺设钢纤维混凝土为例,从钢纤维混凝土原材料选用、钢纤维增强机理、配合比设计、钢纤维混凝土生产及泵送等方面进行阐述,配制了高抗折强度等级混凝土,实现了大坍落度钢纤维混凝土泵送施工。     

钢纤维混凝土施工与泵送技术探析

文中分析了泵送钢纤维混凝土施工特点及压力损失影响的主要因素，并结合项目实例，阐述了混凝土制作、运输以及输送设备管道布置等方面的施工控制方法，以期为优化施工质量控制提供参考。     

钢纤维混凝土施工质量控制

主要介绍深圳集建国际广场钢纤维混凝土施工。项目QC小组通过科学地运用QC方法,攻克了钢纤维混凝土泵送施工技术难点,混凝土泵送施工顺利,取得了良好的社会效果。     

Experimental behaviour of eccentrically loaded slender circular hollow steel columns in-filled with fibre reinforced concrete

This paper is based on the experimental study of twelve slender steel tubular columns of circular sections filled with both plain and fibre reinforced concrete. The specimens were tested under eccentric compression to investigate the effects of fibre reinforced concrete on the strength and behaviour of slender composite columns. The slenderness ratio was considered to be the main test parameter. Hollow steel sections of similar specimens were also tested as reference columns. The test results were illustrated by load-deflection and load-strain curves. Various characteristics such as strength, stiffness, ductility, energy absorption capacity and failure mode are discussed. Interpretation of the experimental results indicates that the use of fibre reinforced concrete as infill material has a considerable effect on the strength and behaviour of slender composite columns.     

钢纤维混凝土配合比设计试验研究

钢纤维混凝土是近年来迅速发展并逐渐获得应用的新型复合材料,虽然现在已经普遍应用,但至今没有相应的配合比设计规范出现,结合有关混凝土配合比设计规范和钢纤维混凝土教程,以实例介绍了钢纤维混凝土最优配合比的确定.试验结果对钢纤维混凝土在工程中的应用具有一定的参考价值.     

国家大剧院工程C30P16纤维混凝土的研制与应用

优化配合比的基准混凝土中，掺入聚丙烯纤维丝和粉煤灰，配制出的纤维抗掺混凝土，其抗拉、抗折强度提高，并有良好的抗渗漏、防裂性能，可有效改善混凝土的耐久性。在国家大剧院工程基础底板及地下室外墙采用了C30P16防裂抗渗纤维混凝土，搅拌出机后纤维丝分散均匀，拌合物有良好的保水性和粘聚性，泵送性能优良，混凝土强度和抗渗等级均满足设计要求。     

钢纤维混凝土特性及其井壁结构试验研究

通过对不同钢纤维掺量的混凝土试块进行力学特性研究,其中采用劈裂法和套筒致裂法对钢纤维混凝土试件抗拉强度的分布特征进行分析,并对比普通混凝土力学特征数据,反映出混凝土在抗拉强度、韧性等方面得到很大提高。通过井壁模型试验的研究,钢纤维混凝土确实是千米深井井壁支护的理想材料。     

Flowability of fibre-reinforced concrete and its effect on the mechanical properties of the material

Fibre distribution is an important factor, affecting both the fresh- and hardened-state properties of concrete. The paper describes a study in which the fibre distribution and orientation were investigated by means of a suitable technique, by using a translucent fluid model with a yield stress (Carbopol 940). The observation confirmed the ability of the developed method to provide data on the orientation and distribution of steel fibres within concrete. It was showed that orientation and distribution are dependent on the yield stress of the fluid material. Concrete specimens, containing 0.5% of 35 mm long hooked steel fibres, were also cast and tested under four-point loading, in order to study the correlation between rheology, fibre distribution and the mechanical properties of steel fiber-reinforced concrete. The results confirm that the rheology of concrete has an important influence on the orientation of the fibres. The flexural strength depends on the fibre distribution and orientation and is significantly improved when the fibres are oriented in the direction of the tensile stresses fresh (concrete with good workability). On the contrary, for concrete with poor workability, an inadequate orientation of fibres occurred, leading to a poor contribution of the fibres to the flexural behaviour of the tested specimens, despite the relatively higher compression strength of the tested concrete material.     

Influence of yield stress and compressive strength on direct shear behaviour of steel fibre-reinforced concrete

This study aims in examining the influence of the paste yield stress and compressive strength on the behaviour of fibre-reinforced concrete (FRC) versus direct shear. The parameters studied are the steel fibre contents, the aspect ratio of fibres and the concrete strength. Prismatic specimens of dimensions 10 × 10 × 35 cm made of concrete of various yield stress reinforced with steel fibres hooked at the ends with three fibre volume fractions (i.e. 0%, 0.5% and 1%) and two aspects ratio (65 and 80) were tested to direct shear. Three types of concretes with various compressive strength and yield stress were tested, an ordinary concrete (OC), a self-compacting concrete (SCC) and a high strength concrete (HSC). The concrete strengths investigated include 30 MPa for OC, 60 MPa for SCC and 80 MPa for HSC.The results show that the shear strength and ductility are affected and have been improved very significantly by the fibre contents, fibre aspect ratio and concrete strength. As the compressive strength and the volume fraction of fibres increase, the shear strength increases. However, yield stress of concrete has an important influence on the orientation and distribution of the fibres in the matrix. The ductility was much higher for ordinary and self-compacting concretes (concrete with good workability). The ductility in direct shear depends on the fibre orientation and is significantly improved when the fibres are perpendicular to the shear plane. On the contrary, for concrete with poor workability, an inadequate distribution and orientation of fibres occurred, leading to a weak contribution of the fibres to the direct shear behaviour.     

钢纤维混凝土单轴拉伸实验方法

在介绍了混凝土单轴拉伸试验中试件的形状及受力方式的基础上,对其中的内埋式试验方法进行改进,通过对比分析普通混凝土和钢纤维混凝土的拉伸试验数据,得出在加入钢纤维后,混凝土的抗拉强度和拉伸变形能力都有所提高。     

Modellbildung zur Simulation von Stahlfaserbeton unter hochdynamischer Belastung

Modelling of Steel Fibre Reinforced Concrete under High Dynamic Loadings For structural protection against extraordinary loads it is important to find construction materials that offer properties that are especially applicable to the problem. One of these materials is steel fibre reinforced concrete. However, for high dynamic loads like from impact or detonation steel fibre reinforced concrete is not yet investigated sufficiently. This article describes a new empirical material model for the simulation of steel fibre reinforced concrete under high dynamic loadings. This material model also includes a damage model which describes the degradation of stiffness and strength in consequence of plastic (compaction and shear) strain. The model is implemented in a hydrocode and validated by a multitude of contact detonation tests. From these results it could be shown that the numerical simulations carried out with the new steel fibre reinforced concrete model are capable to complement or to reduce the expensive and time‐consuming experiments, respectively.     

钢纤维掺量对混凝土立方体抗压强度影响的研究

钢纤维的掺量与混凝土立方体抗压强度关系密切,试验证明钢纤维掺量在一定范围内对混凝土可以起到增强作用。在进行钢纤维混凝土设计时应综合考虑混凝土的抗压、抗弯折、抗裂等性能,科学合理的确定钢纤维在混凝土中的掺量。