scholarly journals Theoretical and Numerical Study of Shear Strength of Concrete Material

2020 ◽  
Vol 13 (5) ◽  
pp. 161-168
Author(s):  
Liu Jun ◽  
◽  
Xiang Yuzhou ◽  
Xiong Yucheng ◽  
Wu zusong ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Numerical Study ◽  
Concrete Strength ◽  
Strength Characteristics ◽  
Theoretical Formula ◽  
Concrete Material ◽  
Study Results ◽  
Concrete Materials ◽  
Mohr’S Circle

The shear strength of some concrete materials should be analyzed based on elastic-plastic theory in petroleum, water conservancy, tunnel engineering, and so on. The majority of researches concentrate mainly on the tensile and compressive strength of concretes, but few have studied the shear strength. Concrete materials have been increasingly applied broadly to geotechnical engineering. Thus, investigating the shear strength characteristics of concretes is of great importance. To study the characteristics of shear strength of concrete materials, the theoretical relationship between concrete’s compressive and shear strengths was discussed in the uniaxial, biaxial, and triaxial stress states. The concrete strength envelopes under the biaxial and uniaxial compressive strength were studied. Given the concrete shear strength, the overload method and the finite difference software FLAC3D were used to investigate the concrete failure modes and ultimate bearing capacities. Results show that the theoretical formula under the 3D stress-bearing condition is only applicable to the circumstance with equal compressive strengths under the biaxial and uniaxial conditions, which conforms to 3D Mohr’s circle theory. 3D Mohr’s circle theory is not totally applicable to concrete materials where the concrete compressive strength under the biaxial condition is larger than that under the uniaxial condition. Concrete material gains its shear strength 47 percent from its frictional force while the rest form cohesive force. The study results can provide a certain basis and reference for analyzing the shear strength characteristics of concrete materials.

scholarly journals Shear Strength of Reinforced Recycled Aggregate Concrete Corbels

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ahid Zuhair Hamoodi ◽  
Aqeel Hatem Chkheiwer ◽  
Jaffar Ahmed Kadim
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Failure Load ◽  
Concrete Strength ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Depth Ratio ◽  
Failure Loads ◽  
Effective Depth

This paper is related to a laboratory program for the shear strength of reinforced concrete corbels (RCC) cast with or without recycled aggregate (RA) by investigating the main parameters affecting the corbels behavior including the replacement aggregate recycling ratio, fcu, and shear span to effective depth ratio a/d. Eight specimens were cast and tested. The obtained results were compared with ACI and EC2 codes. It is found that the ACI code and E2 code give sensibly conservative results when compared with the findings of the present work for all tested specimens regarding RA, concrete strength, and a/d. Also, the experimental results show that the presence of recycled aggregate decreases slightly both cracking and failure loads. Furthermore, the failure load development due to the effect of compressive strength is more effective with the presence of recycled aggregate, and the 50% ratio of RA was the suitable ratio in elaborate crack and failure loads. Finally, the reduction of the span-depth ratio (from 0.50 to 0.35) increases the crack and failure load by 8.1% and 20.2%, respectively, leading to confirm that the corbel strength is much sensitive to decreasing span-depth ratio compared to the associated deflections.

scholarly journals Comparative Analysis of Concrete Strength Made from Selected Brands of Cement in Anambra State, Nigeria

2020 ◽  
pp. 1-10
Author(s):  
C. B. N. Bert-Okonkwor ◽  
K. C. Okolie ◽  
F. O. Ezeokoli ◽  
G. C. Ohazulume
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Concrete Strength ◽  
Material Testing ◽  
Strength Characteristics ◽  
Testing Laboratory ◽  
River Sand ◽  
Anambra State ◽  
Fine Aggregates ◽  
Compressive Strength Of Concrete

The strength characteristics of concrete made from different brands of cement used in Anambra State, Nigeria are reported in this paper. Samples of the selected brands of cement were collected and are used in mixing concrete. The study was conducted in Anambra State, Nigeria for 10 months. Samples of the selected brands of cement were collected and are used in mixing concrete. The fine aggregates used was obtained from River Sand (Onitsha), coarse aggregate is 12 mm quarried granite and water used for the concrete mixing is fit for drinking. These samples of concrete are tested in the laboratory (Anambra State Material Testing Laboratory) for workability and compressive strength and the result obtained were presented in simple tables The study found out that the compressive strength (28th day) of BUA, SUPASET, DANGOTE and UNICEM cements were 30.5, 31.70, 29.66 and 29.08 N/mm2, respectively. Also, the result of the slump value ranges from 70–140 (indicating that the concrete mix is workable) for all the four samples. The results indicate that SUPASET yielded the highest compressive strength (28th day) while UNICEM yielded the lowest compressive strength (28th day). The study was concluded by recommending that all the selected brands of cement within the study area met with the required standard. All concrete samples achieved the minimum compressive strength of concrete (i.e., 21 N/mm2) within 7 days of production. Though the popular cement in the study area is DANGOTE, SUPASET cement is the best cement in terms of strength characteristics while UNICEM possesses the least compressive strength.

Experimental Research on the Relationship between Dielectric Constant and Compressive Strength of Cement Concrete Materials

2011 ◽  
Vol 284-286 ◽  
pp. 857-860
Author(s):  
Bei Zhang ◽  
Yan Hui Zhong ◽  
Tao Wang ◽  
Fu Ming Wang
Keyword(s):  
Dielectric Constant ◽  
Compressive Strength ◽  
Experimental Research ◽  
Ground Penetrating Radar ◽  
Cement Concrete ◽  
Concrete Material ◽  
Concrete Materials ◽  
Ground Penetrating ◽  
The Relationship

Dielectric constant is the most important material property which ground penetrating radar(GPR) data reflects. Based on experiment, through the determination of the compressive strength during concrete mixture ages and the real part and imaginary part of dielectric constant, the relationship between dielectric constant and the compressive strength of cement concrete material is studied. It is shown from the achievements that there has feasibility to non-destructively test the cement concrete material compressive strength by using GPR.

scholarly journals Modulus elasticity of the graded concrete, a preliminary research

2018 ◽  
Vol 195 ◽  
pp. 01005 ◽  
Author(s):  
M. Mirza Abdillah Pratama ◽  
B. Sri Umniati ◽  
Bunga Arumsari Mutiara Wulandari ◽  
Ay Lie Han ◽  
Buntara Sthenly Gan ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Modulus Of Elasticity ◽  
Concrete Strength ◽  
Test Results ◽  
Structural Element ◽  
Concrete Material ◽  
Static Modulus ◽  
Preliminary Research ◽  
Static Modulus Of Elasticity

The elastic modulus of materials plays a role in determining the stiffness of a structural element and its level of serviceability. Previous research indicates that the concrete modulus of elasticity could be improved by combining 2 (two) concrete mixes using a gradual compacting method. In this study, the effect of different concrete strength combinations to the resulting modulus of elasticity is examined. Three types of concrete mixes with a strength of 30 MPa, 40 MPa and 50 MPa are prepared. The graded concrete is moulded in cylindrical concrete casts (150 mm x 300 mm) with the following casting configurations: 30-40 MPa, 30-50 MPa, and 40-50 MPa. The static modulus of elasticity test is performed at an age of 28 days using compressometers in accordance with ASTM C469. The test results show that the modulus of elasticity of the graded concrete is proportionally influenced by the stiffness of the higher and the lower concrete material. Additionally, the resulting compressive strength of the graded concrete is determined by the lower concrete strength.

Constitutive equations for reliable projectile penetration analysis into a concrete medium

2019 ◽  
Vol 11 (2) ◽  
pp. 159-184
Author(s):  
Vladimir R Feldgun ◽  
David Z Yankelevsky
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Equation Of State ◽  
Penetration Depth ◽  
Uniaxial Compressive Strength ◽  
Constitutive Equations ◽  
Concrete Strength ◽  
Time History ◽  
Non Linear ◽  
Concrete Target

This article analyzes the fundamental question of the mechanical properties representation in penetration analysis and its effect on the calculated results. Penetration analysis into a concrete target with a specified uniaxial compressive strength was carried out using different material models appearing in software libraries. These models determine the specific material equation of state and shear strength envelope related to the concrete uniaxial compressive strength. Different results were obtained for the same concrete strength. This proves that the unconfined compressive strength is not the governing parameter which determines the projectile penetration characteristics and that a large variation of results is obtained from different models. Analysis was then carried out on a case with documented constitutive properties of a concrete target that was penetrated by an instrumented projectile. The predicted penetration depth and the projectile deceleration time history were compared with the measured data, and very good correspondence was obtained. This proved that the specific properties of the penetrated medium should be incorporated in the analysis to properly predict the penetration event. The study then examined the commonly used approximation of a linearized equation of state and a linear Mohr–Coulomb model, replacing the true non-linear equations of state and the true non-linear shear strength dependence, and the linearized relationships’ effect on the analyzed results was assessed. A detailed study of the solution sensitivity to different parameters of the Mohr–Coulomb relationship then followed, and its effect on different penetration parameters (nose embedment duration, nose embedment velocity, penetration depth, peak deceleration, quasi-static deceleration) has been examined, to demonstrate how a perturbation in assumed concrete properties affects the solution of the penetration problem. The article illuminates the role of the constitutive equations on penetration analysis and the importance of the proper selection of the representative expressions and of their approximations.

scholarly journals Use of Glass Dust to Improve Concrete Strength on Offshore Platform Installations

2019 ◽  
Vol 8 (12) ◽  
pp. 5549-5552
Keyword(s):  
Compressive Strength ◽  
Organic Molecules ◽  
Concrete Strength ◽  
Biodegradable Materials ◽  
Hardened Concrete ◽  
Conventional Concrete ◽  
Concrete Material ◽  
Compressive Strength Of Concrete ◽  
Micro Organisms ◽  
Glass Dust

The primary aim of this study is to investigate the influence of using glass dust as an additional in conventional concrete material on the properties of fresh and hardened concrete. Soil pollution happen when non-biodegradable materials disposed into land. However, the used of this nonbiodegradable can do wonder for construction purposes. This is due to the non- biodegradable materials which cannot be broken down to simple organic molecules by micro-organisms. Glass dust is one of the example of non- biodegradable. Nowadays, the used of this dust becoming more popular due to its properties. In this study, the glass dust which consist of silica has being used as an additional ingredients to concrete cement. The concentrations of the glass has being varies to determine the mechanical properties e.g. compressive strength of M35 grade concrete. The variation of glass dust are from 10, 20 and 30%. The compressive strength of concrete cubes is tested after 7 and 14 days. The outcomes of the study are presented in tables and graphs.

Experimental Study on Non-Autoclaved PHC Pile Concrete Applying Polycarboxylate Superplasticizer

2014 ◽  
Vol 629-630 ◽  
pp. 345-350 ◽  
Author(s):  
Ying Zhan ◽  
Yi Bo Yang ◽  
Xiao Huan Wu ◽  
Yu Hang Xie ◽  
Jian Luo ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Chloride Ion ◽  
High Energy ◽  
Polycarboxylate Superplasticizer ◽  
Chloride Migration ◽  
Study Results ◽  
Binder Ratio ◽  
Electric Flux ◽  
High Energy Consumption

Traditional PHC pile production adopts two-step curing with the disadvantages of high energy consumption, considerable carbon emissions, and easy cracking during construction. In addition, non-autoclaved pipe pile studies involve problems such as adoption of naphthalene based superplasticizer and lengthy coated curing duration, thus leading to their few applications. In order to solve the problems, the study on non-autoclaved PHC pile was conducted to systematically study the impacts of curing system, water-binder ratio, and admixture composition on concrete strength, ratio of tensile and compressive strength, and chloride ion resistance at different ages. Study results show that through the use of a polycarboxylate superplasticizer, an optimal 8-hour curing system and concrete mix ratio, the strength of non-autoclaved concrete reached 93.2MPa within one day, with the ratio of tensile and compressive strength of 6.07%, the coulomb electric flux of 85C, and the chloride migration coefficient of 0.54×10-12m2/s.

PENGKAJIAN KEKUATAN BETON STRUKTUR JEMBATAN PASCA KEBAKARAN

2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Sudarmadi Sudarmadi
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Strength Assessment ◽  
Concrete Testing

In this paper a case study about concrete strength assessment of bridge structure experiencing fire is discussed. Assessment methods include activities of visual inspection, concrete testing by Hammer Test, Ultrasonic Pulse Velocity Test, and Core Test. Then, test results are compared with the requirement of RSNI T-12-2004. Test results show that surface concrete at the location of fire deteriorates so that its quality is decreased into the category of Very Poor with ultrasonic pulse velocity ranges between 1,14 – 1,74 km/s. From test results also it can be known that concrete compressive strength of inner part of bridge pier ranges about 267 – 274 kg/cm2 and concrete compressive strength of beam and plate experiencing fire directly is about 173 kg/cm2 and 159 kg/cm2. It can be concluded that surface concrete strength at the location of fire does not meet the requirement of RSNI T-12-2004. So, repair on surface concrete of pier, beam, and plate at the location of fire is required.

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