scholarly journals Study of Flexural Response in Strain Hardening Cementitious Composites Based on Proposed Parametric Model

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 113 ◽  
Author(s):  
Zhanfeng Qi ◽  
Zhiyi Huang ◽  
Hui Li ◽  
Wenhua Chen
Keyword(s):  
Strain Hardening ◽  
Absorption Capacity ◽  
Flexural Behavior ◽  
Bending Test ◽  
Cementitious Composites ◽  
Flexural Response ◽  
Modified Method ◽  
Four Point Bending ◽  
Transition Strain ◽  
The Moment

Strain hardening cementitious composites (SHCCs) are widely used in projects due to their excellent deformation resistance and large energy absorption capacity. However, determining tensile strain capacity is still a challenge for engineers. The current popular approach is to use inverse methods to predict the tensile behavior of SHCCs, such as the UM method (Qian and Li) and the JCI (Japan Concrete Institute) method. The key to these two approaches is to acquire the exact relationship between the bending and the uniaxial response. In this paper, a reasonable linear constitutive model of the SHCCs is modified. Initially, the moment-curvature diagrams are discussed by material parameters. The results reveal that the moment-curvature response is quite sensitive to the variations in the parameter of transition strain α, post-cracking tensile stiffness η, and strain softening stiffness μ, however, for the compressive parameters, the moment-curvature responses influence on flexural behavior is insignificant. Moreover, the load-deflection curve in the mid-span of SHCC, based on the consideration of shear effect, is simulated under a four-point bending test (FPBT). The results show a remarkable consistency with the experimental data when compared to the previous simulations. It is expected that this modified method can enhance an accurate program in order to obtain the tensile capacity.

scholarly journals Performance of Strain hardening cementitious composite as strengthening and protective overlay in flexural members

2018 ◽  
Vol 199 ◽  
pp. 09005 ◽  
Author(s):  
Sardar Umer Sial ◽  
M. Iqbal Khan
Keyword(s):  
Strain Hardening ◽  
Protective Layer ◽  
Bending Test ◽  
Rc Beams ◽  
Crack Control ◽  
Concrete Overlays ◽  
Flexural Response ◽  
Four Point Bending ◽  
Beam Height ◽  
Scale Control

Strain-hardening cementitious composites (SHCC) are advanced type of cement-based composite materials having superior crack control and tensile properties. Owing to such characteristics, SHCC can be used for strengthening and crack-width control of structural members. This paper presents a study on the flexural response of reinforced concrete (RC) beams with different overlays of SHCC. The work consists of RC-SHCC overlay beams, in which SHCC overlays of different thicknesses (15% and 30% of beam height, plus cover) and reinforcement ratios (0% and 0.4%) were cast at the bottom of the RC beams. The performance of the RC-SHCC overlay beams was compared with control RC beams having concrete overlays of similar parameters. A series of eight laboratory-scale control and composite beam specimens were tested under four-point bending test. From the experimental results, it was observed that RC-SHCC overlay beams showed improved flexural capacity and crack control as compared to that of control beams. The beams with unreinforced SHCC overlays showed significant improvement at service stage, while beams with reinforced SHCC overlays showed significant improvement at peak stage. The SHCC overlay beams without reinforcement have showed improved ductility as compared to control beams with concrete overlays. Additionally, the SHCC overlays performed as a protective layer for controlling the crack widths in the composite beams.

Flexural Behavior of Six Species of Italian Bamboo

2022 ◽  
Author(s):  
Silvia Greco ◽  
Luisa Molari
Keyword(s):  
Structural Material ◽  
Flexural Strength ◽  
Mechanical Performance ◽  
Functionally Graded ◽  
Flexural Behavior ◽  
Bending Test ◽  
Bamboo Species ◽  
Four Point Bending ◽  
Flexural Ductility ◽  
Graded Material

The good mechanical performance of bamboo, coupled with its sustainability, has boosted the idea to use it as a structural material. In some areas of the world it is regularly used in constructions but there are still countries in which there is a lack of knowledge of the mechanical properties of the locally-grown bamboo, which limits the spread of this material. Bamboo is optimized to resist to flexural actions with its peculiar micro structure along the thickness in which the amount of fibers intensifies towards the outer layer and the inner part is composed mostly of parenchyma. The flexural strength depends on the amount of fibers, whereas the flexural ductility is correlated to the parenchyma content. This study focuses on the flexural strength and ductility of six different species of untreated bamboo grown in Italy. A four-point bending test was carried out on bamboo strips in two different loading configurations relating to its microstructure. Deformation data are acquired from two strain gauges in the upper and lower part of the bamboo beam. Difference in shape and size of Italian bamboo species compared to the ones traditionally used results in added complexity when performing the tests. Such difficulties and the found solutions are also described in this work. The main goal is to reveal the flexural behavior of Italian bamboo as a functionally graded material and to expand the knowledge of European bamboo species toward its use as a structural material not only as culm but also as laminated material.

Study on the Preparation of Green and Environmentally Friendly High Toughness Cementitous Composites with Large Amount of Fly Ash

2020 ◽  
Vol 996 ◽  
pp. 97-103
Author(s):  
Xiang Rong Cai ◽  
Bai Quan Fu ◽  
Zhi Gang Liu
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Strain Hardening ◽  
Cementitious Composites ◽  
Special Focus ◽  
Type I ◽  
Flexural Performance ◽  
High Toughness ◽  
Four Point Bending ◽  
Pva Fiber

In order to reduce the environmental burden and the energy consumption of PVA fiber reinforced high toughness cementitious composites, special focus is placed on the influence of fly ash type and content and curing type on the flexural performance of high toughness cementitious composites through four-point bending tests. The high toughness cementitious composites without fly ash have been used in the program for comparison purpose. The tests results show that, compared with the basic high toughness cementitious composites, the flexural strength decreases and the deflection increases with the s/b increasing when the fly ash is added. The increase in fly ash content results in an improvement of strain hardening property and increases in both flexural strength and deflection, which show that fly ash is benefit to the pseudo strain hardening performance. However the effects of fly ash type and curing type are not obvious on the load but obvious on the deflection. The deflection of high toughness cementitious composites with type I fly ash or water curing is higher than that of type II or standard curing. It is demonstrated that all the high toughness cementitious composites studied in this paper exhibit strain-hardening and multiple cracking through adding fly ash.

Study on the Flexural Property of PVA-High Toughness Cementitious Composites

2011 ◽  
Vol 250-253 ◽  
pp. 765-768
Author(s):  
Wen Ling Tian ◽  
Lei Xu ◽  
Xiao Wei Wang
Keyword(s):  
High Performance ◽  
Tensile Elongation ◽  
Bending Test ◽  
Uniaxial Tensile ◽  
Cementitious Composites ◽  
Flexural Property ◽  
Uniaxial Tensile Test ◽  
Normal Concrete ◽  
Flexural Performance ◽  
Four Point Bending

For the compressive strength of the normal concrete is high and the tensile strength is low, it is typically brittle material. The ultimate tensile elongation of it is insufficiently 1/1000. Zhongwei Wu, an academician of Chinese Academy of Engineering pointed out that compounding cementitious composites was the way to make it high-performance, and fiber reinforced was the key[1]. Polyvinyl Alcohol Engineered Cementitious Composites has super flexural performance[2] and stretching ability[3],and its ultimate deflection is approximately 40 times larger than that of normal concrete when bended, similar to the multiple cracking and super toughness of uniaxial tensile test, it shows significant bending hardening behavior in the process of the test. This paper studied its flexural property by four point bending test .

Influence of Fly Ash on the Mechanical Properties of Engineered Cementitious Composites Cured at High Temperature

2010 ◽  
Vol 113-116 ◽  
pp. 1293-1296
Author(s):  
Yu Zhu ◽  
Ying Zi Yang ◽  
Hong Wei Deng ◽  
Yan Yao
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
High Volume ◽  
Bending Test ◽  
Cementitious Composites ◽  
Test Results ◽  
Four Point Bending ◽  
High Volume Fly Ash ◽  
Compressive Strength Test

In order to investigate the mechanical properties of cementitious composites (ECC) cured at 60°C, four-point bending test and compressive strength test are employed to analyze the effect of fly ash on the properties of ECC. The replacement ratio of cement with fly ash is 50%, 70% and 80%, respectively. The test results indicate that ECC with high volume fly ash still remain the characteristic of pseudo-strain hardening and the deflection of ECC increases remarkably by adding more fly ash. The observations of ECC indicate that the crack width is relatively smaller for higher volume fly ash ECC. Meanwhile, compressive strength of ECC specimens with 80% fly ash can reach to 70MPa. This is helpful to produce precast ECC with high volume of fly ash.

Evaluation of the Design Mix Proportion on Mechanical Properties of Engineered Cementitious Composites

2018 ◽  
Vol 775 ◽  
pp. 589-595 ◽  
Author(s):  
Lee Siong Wee ◽  
Oh Chai Lian ◽  
Mohd Raizamzamani Md Zain
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fiber Content ◽  
Flexural Behavior ◽  
Bending Test ◽  
Cementitious Composites ◽  
Sand Content ◽  
Flexural Behaviour ◽  
Normal Concrete ◽  
Engineered Cementitious Composites

This paper investigates the mechanical properties of engineered cementitious composites (ECC) in terms of compressive strength and flexural behaviour. A new version of ECC made of cement, ground granulated blast-furnace slag (GGBS), local sand, polypropylene (PP) fibers, water and superplasticizer (SP) was employed in this study. Few series of ECC mixtures were designed, cast, and tested in compression and flexural after 28 days of curing. The effect of the fiber content and sand content were studied in different cement-GGBS combination. Compression test results indicated that all ECC mixtures obtained at least 1.8 times compressive strength compared to normal concrete. They also demonstrated more ductile flexural behavior compared to normal concrete from three-point bending test. Increasing fiber content from 1.5% to 2.0% and 2.5% has negative effect on compressive strength but significantly improved modulus of toughness of ECC mixtures. The compressive strength of ECC was reduced when the sand to binder ratio adjusted to 0.4 and 0.6. The flexural behaviour of ECC was slightly improved with the increasing of sand content.

EXPERIMENTAL STUDY ON FLEXURAL BEHAVIOR OF STEEL-CONCRETE COMPOSITE BEAM COMPRISING PRECAST COMPOSITE SLABS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Hetao Hou ◽  
Mingyuan Feng ◽  
Lu Geng ◽  
Lei Chen ◽  
Haining Liu
Keyword(s):  
Prestressed Concrete ◽  
Composite Beam ◽  
Flexural Rigidity ◽  
Flexural Behavior ◽  
Bond Slip ◽  
Floor Slab ◽  
Shear Connection ◽  
Four Point Bending ◽  
The Moment

Four-point bending tests including twelve specimens were carried out to investigate the flexural rigidity, failure mode and ultimate capacity of the steel-concrete composite beam with a composite floor slab comprising 30 mm thick precast prestressed concrete panels and T-shaped concrete ribs (PPCRP). The test parameters included support length of PPCRP, thickness of the composite floor slab, longitudinal compressive reinforcement ratio, degree of the shear connection and the direction of T-shaped concrete rib. Strain distribution along the depth of mid-span section was obtained by strain gauges. Based on the moment-deflection curves of specimens, it was showed that flexural behavior of precast composite floor slab was similar to that of concrete floor slab cast in-situ during the elastic stage. Two failure phenomena were observed: i) Interface bond slip between the precast panel and the cast in-situ layer; ii) Diagonal shear crushing in one shear span. Compared with the floor slab cast in-situ, a slight decline in the ultimate flexural capacity was observed for the composite beam with composite floor slab. Analyses about the effects of all parameters on composite beams’ rigidity and ductility were presented.

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