Experimental Investigations of Shear Lag Effect in Orthotropic Composite Box Beam

2010 ◽  
Vol 150-151 ◽  
pp. 1750-1753
Author(s):  
Ya Ping Wu ◽  
Yin Hui Wang ◽  
Li Xia Wang ◽  
Zu Guang Bian
Keyword(s):  
Compressive Strength ◽  
High Strength ◽  
Experimental Investigations ◽  
Curing Time ◽  
Hydration Products ◽  
Shear Lag ◽  
Box Beam ◽  
Lag Effect ◽  
Composite Box Beam ◽  
Resistance Value

The influence of curing time on the mechanical property of the phosphoaluminate cement (PAC) was investigated, and the mechanism was discussed as well. The phase composition and morphology of hydration products, electrical properties, porosity and pore size distribution of PAC cured different age were analyzed with XRD, EIS and MIP. The results showed PAC has the property of early-high strength, and the compressive strength of PAC cured for 1 day was about 70% of 28 days’. The main hydration products of PAC are micro-crystal phase and gel of phosphate and phosphoaluminate which formed compacter microstructure. In addition, there are no calcium hydroxide (CH) and ettringite (AFt) produced during the process of hydration. The compressive strength of PAC increased with age, which was due to more products continuously produced. The ac resistance analysis manifested as the change of the nyquist pattern and resistance value.

Mechanical Property of Phosphoaluminate Cement

2010 ◽  
Vol 150-151 ◽  
pp. 1754-1757 ◽  
Author(s):  
Peng Liu ◽  
Zhi Wu Yu ◽  
Ling Kun Chen ◽  
Zhu Ding
Keyword(s):  
Mechanical Property ◽  
Compressive Strength ◽  
Phase Composition ◽  
Electrical Properties ◽  
Pore Size Distribution ◽  
Pore Size ◽  
High Strength ◽  
Curing Time ◽  
Hydration Products ◽  
Resistance Value

The influence of curing time on the mechanical property of the phosphoaluminate cement (PAC) was investigated, and the mechanism was discussed as well. The phase composition and morphology of hydration products, electrical properties, porosity and pore size distribution of PAC cured different age were analyzed with XRD, EIS and MIP. The results showed PAC has the property of early-high strength, and the compressive strength of PAC cured for 1 day was about 70% of 28 days’. The main hydration products of PAC are micro-crystal phase and gel of phosphate and phosphoaluminate which formed compacter microstructure. In addition, there are no calcium hydroxide (CH) and ettringite (AFt) produced during the process of hydration. The compressive strength of PAC increased with age, which was due to more products continuously produced. The ac resistance analysis manifested as the change of the nyquist pattern and resistance value.

Coupled Mechanism on Interfacial Slip and Shear Lag for Twin-Cell Composite Box Beam Under Even Load

2017 ◽  
Vol 34 (5) ◽  
pp. 601-616 ◽  
Author(s):  
J. Yu ◽  
S. W. Hu ◽  
Y. C. Xu ◽  
B. Fan
Keyword(s):  
Composite Structures ◽  
Structural Features ◽  
Interfacial Slip ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Closed Form Solutions ◽  
Concrete Plate ◽  
Box Beam ◽  
Lag Effect ◽  
Composite Box Beam

AbstractA model of Twin-cell Composite Box Beam (TCCBB), which is composed of concrete plate and thin-walled steel box beam with twin-cell, is proposed in this paper. Combined with structural features, longitudinal interfacial slip mode (LISM) and related shear hysteresis functions (SHFS) of this TCCBB model are defined respectively; analytical formulation describing combination effect between interfacial slip and shear lag is launched for this TCCBB model under even load. Based on established governing differential equations and its relative boundary conditions (calculated with compatible mechanism of interfacial slip and shear lag effect), closed form solutions of normal stress and shear stress are derived for this TCCBB model, as well as effective shear-lag coefficient and effective coupled behavior coefficient. To obtain more accurate computational results of specific coupled mechanism of this TCCBB model, numerical example is carried out to analyze and predict coupled mechanism of interfacial slip and shear lag effect for this type of composite structures.

Experimental Investigations of Shear Lag Effect in a Simply Supported [0o ∕±45o2 ∕ 0o]T Laminated Box Beam

2011 ◽  
Vol 117-119 ◽  
pp. 858-861
Author(s):  
Ya Ping Wu ◽  
Zhi Xiang Zha ◽  
Li Xia Wang ◽  
Yin Hui Wang
Keyword(s):  
Structural Engineering ◽  
High Efficiency ◽  
Experimental Investigations ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Normal Stress Distribution ◽  
Lag Effects ◽  
Box Beam ◽  
Lag Effect ◽  
Thin Walled

With the features of high efficiency, low consumption and good mechanical characteristic, thin-walled composite box beams have been broadly adopted in structural engineering, and its mechanical behavior has became an active research area. As shear lag effect can bring an uneven normal stress distribution on the flanges, it would remarkably affect the strength design of thin-walled beams. This paper focuses on the experimental investigations of shear lag effects in [0o∕±45o2∕ 0o]T laminated box beam under concentrated loads, and test results indicates that the shear lag effect in this composite box beam can be simulated by the two parabola.

Effect of CO2 Curing on the Strength of High Strength Pervious Concrete

2020 ◽  
Vol 846 ◽  
pp. 207-212
Author(s):  
Ming Gin Lee ◽  
Yung Chih Wang ◽  
Wan Xuan Xiao ◽  
Ming Ju Lee ◽  
Tuz Yuan Huang
Keyword(s):  
Carbon Dioxide ◽  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
High Strength ◽  
Pervious Concrete ◽  
Control Group ◽  
Curing Time ◽  
Compressive Strength Of Concrete ◽  
Curing Pressure

This study was conducted to assess the effect of CO2 curing on the compressive strength of high strength pervious concrete. The factors studied to evaluate compressive strength of concrete on CO2 curing pressure, curing time, and age of specimen at testing. Three Aggregate sizes, three CO2 curing pressures, three CO2 curing time, and three testing ages were used in this investigation. The research tried to produce a high strength pervious concrete and use carbon dioxide for curing to find out whether it could enhance the compressive strength. The results show that the compressive strength of the control group increases rapidly and its 90-day compressive strength closed to 60 MPa. The 1-day compressive strength has a major impact after CO2 curing and their strength decreased by about 0% to 50% as compared to the control group. However, it is observed that there is only slight difference in relationship between modulus of elasticity and compressive strength obtained from 100 by 200mm cylinders with CO2 curing.

Theoretical and Experimental Investigations on Shear Lag Effect of Double-Box Composite Beam with Wide Flange under Symmetrical Loading

2015 ◽  
Vol 31 (6) ◽  
pp. 653-663 ◽  
Author(s):  
S.-W. Hu ◽  
J. Yu ◽  
Y.-Q. Huang ◽  
S.-Y. Xiao
Keyword(s):  
Composite Beam ◽  
Experimental Investigations ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Theoretical Derivation ◽  
Energy Principle ◽  
Lag Effect ◽  
Symmetrical Loading ◽  
Stress Behaviors ◽  
Minimum Potential Energy Principle

ABSTRACTA new type of steel-concrete composite beam with double-box cross-section is proposed in this paper. In order to investigate stress behaviors and deflection characteristics of such composite beam with wide flange considering the shear lag effect, theoretical analysis and experimental study are launched simultaneously. Based on the minimum potential energy principle, governing differential equations in view of the shear lag effect are deduced by energy variational method, and analytical solutions of it's stress and deflection under the effect of symmetrical loading are calculated. The preceding analyses show that relative error is less than 14.71%, with a good agreement, and farther show that this method of theoretical derivation, which is used for analyzing shear lag effect of composite beam with wide flange, has certain reference and guidance.

The Research of Box Beam Warping Displacement Function

2014 ◽  
Vol 578-579 ◽  
pp. 868-871
Author(s):  
Yu Ping Yue ◽  
Rong Zheng Cui
Keyword(s):  
Displacement Function ◽  
Shear Lag ◽  
Box Girder ◽  
Effect Analysis ◽  
Displacement Mode ◽  
Box Beam ◽  
Lag Effect ◽  
Beam Shear ◽  
Minimum Potential ◽  
Warping Displacement

Based on the principle of minimum potential energy, choosing warping displacement function of parabolic displacement mode, using energy variational method to deduce Box beam shear lag effect analysis of differential equation to obtain shear lag warping stress. Through the calculation of simply supported box girder model and the analyse of the stress of Wide cantilever plate, box girder roof and box girder floor Assume a new warping displacement function. Through the analysis of measured results proved the rationality of this article assumes and research value.

The The Characterization and Modeling the Mechanical Properties of High Strength Concrete (HSC) Modified with Fly Ash (FA)

2020 ◽  
Vol 38 (2A) ◽  
pp. 173-184 ◽  
Author(s):  
Saman M. Kamal ◽  
Jalal A. Saeed ◽  
Ahmed Mohammed
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Curing Time ◽  
Strength Concrete ◽  
Statistical Variation ◽  
Study Results ◽  
Concrete Testing ◽  
Linked Model

One of the main challenges facing Civil Engineering community is to modify cement quantity in the mix design by admixtures to enhance the mechanical properties. According to more than 1000 data from literature, mechanical characteristics of concrete modified with FA were discussed. The statistical variation with modeling were achieved by set of data. The cement was replaced up to 70% with FA (weight of dry cement) and by cube of concrete testing up to 90 days of curing time and different w/c ratio. The compressive strength of concrete varied from 18-67 MPa, while, for modified concrete with FA, compressive strength ranged from 21-94 MPa, tensile strength ranged from 1-9 MPa and flexural strengths ranged from 3 - 10 MPa. The w/c ratio of concrete modified with FA varied from 0.24-0.53, also the FA content varied from 0-50 %. Vipulanandan correlation model was effective by connecting mechanical properties and compare with Hoek-Brown model. The nonlinear model was used to investigate the effect of FA on properties of normal and high strength concrete. Study results presented a worthy correlation between compressive strength and curing time, w/c ratio and FA content. By using the interactive linked (model) for compressive, tensile, and flexural strengths of concrete quantified well as a function of w/c ratio, curing time and FA content by using a nonlinear relationship.

A CURVED BOX BEAM ELEMENT CONSIDERING SHEAR LAG EFFECT AND ITS STATIC AND DYNAMIC APPLICATIONS

2002 ◽  
Vol 253 (5) ◽  
pp. 1131-1139 ◽  
Author(s):  
WU YAPING ◽  
LAI YUANMING ◽  
ZHU YUANLIN ◽  
PAN WEIDONG
Keyword(s):  
Beam Element ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Beam ◽  
Lag Effect

Preparation of α High-Strength Gypsum from FGD Gypsum by Autoclaved Semi-Dry Process

2014 ◽  
Vol 1051 ◽  
pp. 230-236
Author(s):  
Ying Li ◽  
Peng Xuan Duan ◽  
Yuan Chao Miao ◽  
Qing Li
Keyword(s):  
Compressive Strength ◽  
Reaction Time ◽  
Citric Acid ◽  
Aspect Ratio ◽  
High Strength ◽  
Hydration Products ◽  
Fgd Gypsum ◽  
Dry Process ◽  
Conventional Process ◽  
New Process

This paper introduced the characteristics of α high-strength gypsum preparation from FGD gypsum by autoclaved semi-dry process. The compositions of the product in different stages of the reaction and the effects of crystal modifiers on the morphology of the α-HH crystals were examined and compared. The properties of α-HH and the feature of hydration products of α-HH were investigated. The results indicated that the α-HH crystals were well-shaped with the aspect ratio of 1 and the compressive strength of the α-HH could reach or exceed 60MPa. In the new process, the reaction time could be significantly shortened to 2.5hrs, which was much shorter than the conventional process. This process could be widely applied to prepare α high-strength gypsum with phosphogypsum, citric acid gypsum, etc.

Shear Lag and Related Parameter Impact Researches for Twin-Cell Composite Box Beam Under Concentrated Loads

2017 ◽  
Vol 33 (4) ◽  
pp. 443-460 ◽  
Author(s):  
J. Yu ◽  
S. W. Hu ◽  
Z. G. Zhang ◽  
C. J. Wei
Keyword(s):  
Composite Structure ◽  
Virtual Work ◽  
Concrete Slab ◽  
Shear Lag ◽  
Concentrated Loads ◽  
Related Parameter ◽  
Displacement Mode ◽  
Box Beam ◽  
The Impact ◽  
Composite Box Beam

AbstractAn analytical solution is launched for Twin-cell Composite Box Beam (TCCBB) considering the impact of shear lag effects of concrete slab and twin-cell steel girder. To in-depth explore its mechanical mechanism, a new warping displacement mode of wide flange is chosen to meet the essential deformation feature of this TCCBB model by authors. Combining the virtual work principle with the thin-walled beam theory, its governing equations and boundary conditions are established for the TCCBB model. Closed form solutions for longitudinal strain and its shear lag coefficients are also derived under concentrated loads. What's more, experiment investigation and related parameter impact analysis are carried out for this established TCCBB model. Through this research, it shows that the proposed method can be applied to describe and predict shear lag behaviors for this type of composite structure. That further suggests that it provides a certain reference value for engineering design and its late reinforcement and maintenance in the composite structure.

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