scholarly journals Effect of basalt aggregates and plasticizer on the compressive strength of concrete

2015 ◽  
Vol 4 (4) ◽  
pp. 520 ◽  
Author(s):  
Mohammad Al-Rawashdeh ◽  
Ashraf Shaqadan

The purpose of this research is to investigate the feasibility of using basalt aggregates and plasticizers in concrete mixes. An elaborate experimental program that included a variation of plasticizer and basalt in concrete mixes. The laboratory investigation included measurements of sieve analysis, compressive strength, and slump test. The compressive test was evaluated at 7, 14, 28 days of curing time. The results show significant improvement in concrete strength up to 2% of additive plasticizer after that concrete strength was reduced.

2020 ◽  
Vol 846 ◽  
pp. 207-212
Author(s):  
Ming Gin Lee ◽  
Yung Chih Wang ◽  
Wan Xuan Xiao ◽  
Ming Ju Lee ◽  
Tuz Yuan Huang

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.


2019 ◽  
Vol 14 (2) ◽  
Author(s):  
Syifa Fauziah ◽  
Anisah Anisah ◽  
Sittati Musalamah

This research aims to determine the maximum compressive strength value of concrete speedcrete using naphthalene additive additive at each test age and compare with normal concrete 28 days. This research used cylindrical test object with diameter 15 cm and height 30 cm. Speedcrete concrete does not undergo the treatment process while the normal concrete test object through the treatment process. Testing compressive strength of concrete speedcrete using Crushing Test Machine tool. In this research the compressive strength was produced by using superplasticizer type naphthalene and compared with normal concrete without using additive. The target quality plan is fc '35 MPa with the use of additive dose of 1.7% of the weight of cement. The results of this research showed an increase in the value of compressive strength of concrete speedcrete with aadditive materials added naphthalene increased with increasing age of concrete. The results showed that the compressive strength of concrete speedcrete with naphthalene additive materials of 12 hours, 18 hours, 28 hours and 48 hours was 0.5 MPa, 17,81 MPa, 31,14 MPa and 45,77 MPa. Normal strength concrete strength with the addition of 20% water age 28 days that is equal to 54.76 MPa.


2021 ◽  
Author(s):  
DENNIS SANTOS TAVARES ◽  
BRUNA CAMPOS AMARAL ◽  
DAVID AUGUSTO RIBEIRO ◽  
TADAYUKI YANAGI JUNIOR ◽  
FRANCISCO CARLOS GOMES ◽  
...  

Concrete is the main material used in the construction industry and its main property is the axial compressive strength. Usually the prediction of compressive strength is restricted to limited empirical equations and / or laboratory dosages. The objective of this study is to develop fuzzy systems capable of obtaining the axial compressive strength of concrete, from the mixtures and curing time. Several fuzzy systems were developed with Mamdani inference and different defuzzification methods. Triangular membership functions were adopted for the input variables in all systems and triangular functions for the output variables. The developed models were simulated and evaluated using three statistical indexes. The systems with Mamdani inference and centroid, bisector and mom defuzzification proved to be reliable and highly effective. The best performance was obtained by the fuzzy centroid defuzzification system according to the analyses.,


2012 ◽  
Vol 204-208 ◽  
pp. 3970-3973
Author(s):  
Reagan J. Case ◽  
Kai Duan ◽  
Thuraichamy G. Suntharavadivel

As a part of a large research program aiming at the cementitious materials containing recycled materials at Central Queensland University – Australia, the current paper presents the preliminary results of a study on the effects of fly ash, which is used to replace cement in concrete, on the concrete compressive strength. For this purpose, systematic experiments have been carried out to investigate the influences of fly ash ratio and age. The compressive strength of concrete specimens with replacement ratios of 15%, 30% and 45%, and aged 7 and 28 days are measured and are compared with those of the concrete specimens without fly ash at the same ages. The results demonstrate that the strength of fly ash containing concrete improves more slowly but more strongly with aging, than their fly ash free counterparts, and an optimum fly ash replacement ratio exists where the maximum compressive strength of fly ash containing concrete can be achieved, and the maximum strength for the specimens aged 28 days and above is higher that of fly ash free concrete. Furthermore, the observation strength behaviours are analysed and discussed in terms of the influences of fly ash on interface reactions and interface bonding strength.


2019 ◽  
Vol 289 ◽  
pp. 06001
Author(s):  
Serkan Karatosun ◽  
Muhammet Asan ◽  
Oguz Gunes

Rapid and reliable condition assessment of reinforced concrete structures in high seismicity regions is a priority task in estimating their seismic safety. Non-destructive testing (NDT) methods may contribute to the condition assessment practice by providing fast and reliable strength estimation while causing minimal or no damage to the structure. Drilling resistance is an NDT method that has been used for mechanical characterization of natural stone and wood by measuring the force response for constant penetration rate and rotational speed. This paper focuses on the relationship between drilling resistance and compressive strength of concrete, including when it is combined with other NDT methods. Concrete cube samples produced using 6 different concrete mixtures were tested. Correlation equations were then obtained using statistical analysis. The results reveal that it may be possible to reliably estimate the compressive strength of concrete using drilling resistance method.


2018 ◽  
Vol 1145 ◽  
pp. 106-111
Author(s):  
De Jia Liu ◽  
Mei Jun Chen ◽  
Li Xue ◽  
Fan He ◽  
Jian Hu

With the rapid development of construction, the high quality of the construction material is required. Mixing carbon fiber in concrete attracts more and more attention as it can reinforce concrete. However, the science research and engineering application of carbon fiber reinforced concrete is relatively few. In this paper, the effects of different mixing amount of carbon fiber and the sand ratio in concrete and the curing time of concrete and relationships between these factors were investigated. Proper carbon fiber and sand ratio can promote the compressive strength of concrete and it has a good resistance to cracking. The compressive strength of concrete with different mixing amounts of carbon fiber peaks when the sand ratio was 31% and the compressive strength was better when the carbon fiber mixing amount was 0.2% and 1% than any other ratios after 28 days. When the sand ratio was 31%, the compressive strength of carbon fiber mixing amount increased with the increase of curing time and it reached the top when the carbon fiber ratio was 0.8%. The mixing amount of carbon fiber also had a great influence on the early compressive strength to some extent. We anticipate that the research can offer certain reference for engineering practice.


2019 ◽  
Vol 15 (1) ◽  
pp. 26-35
Author(s):  
Anca Ionescu ◽  
Adelina Apostu ◽  
Dan Paul Georgescu

Abstract The compressive strength of the concrete measured at 28 days is the criterion for assessing the concrete class, and these values will be acceptable precise indications for other physical and mechanical characteristics of the concrete. In addition to the factors the compressive strength of concrete varies on (such as: the characteristics and proportion of constituents, the placement conditions and subsequent treatment and testing conditions), the concrete class should also depend on the type of cement contained and the concrete strength evolution over time. Due to the fact that concretes with composite cements have a slower evolution of compressive strength and a significant strength increase after 28 days, concretes with different types of cements and mineral admixtures were tested for compression after 28 days in order to determine the reference time for such tests – and thus the concrete’s class.


2012 ◽  
Vol 5 (6) ◽  
pp. 757-780 ◽  
Author(s):  
E. Pereira ◽  
M. H. F. de Medeiros

To estimate the compressive strength of concrete is necessary in many reinforced concrete structures inspection works. In Brazil, the standard tests for this purpose are: Compressive test in drilled cores, rebound hammer test and ultrasonic test. In the United States and Europe are also regulated other techniques. The aim of this paper is to analyze the use of Pull Off test as an inspection tool of concrete and also disclose the possibility of use of complementary techniques to the standard ones in Brazil. The results show that the Pull Off test results in high correlation (R²> 0.93) with the compressive strength, measured in cylindrical and prismatic specimens. The rebound hammer test did not show satisfactory correlation (R²≅0.6) for the case of cylindrical specimens. The ultrasonic test showed high correlation (R²> 0.98), but behaves differently with the shape changing of the specimens.


2013 ◽  
Vol 438-439 ◽  
pp. 170-173 ◽  
Author(s):  
Hai Ying Yang ◽  
Yi Feng Dong

Support vector machine (SVM) is a statistical learning theory based on a structural risk minimization principle that minimizes both error and weight terms. A SVM model is presented to predict compressive strength of concrete at 28 days in this paper. A total of 20 data sets were used to train, whereas the remaining 10 data sets were used to test the created model. Radial basis function based on support vector machines was used to model the compressive strength and results were compared with a generalized regression neural network approach. The results of this study showed that the SVM approach has the potential to be a practical tool for predicting compressive strength of concrete at 28 days.


2010 ◽  
Vol 163-167 ◽  
pp. 1375-1379 ◽  
Author(s):  
Yi Che ◽  
Sheng Long Ban ◽  
Jian Yu Cui ◽  
Geng Chen ◽  
Yu Pu Song

The purpose of this study is to investigate the influence of specimen size and shape on compressive strength of concrete. Concrete cubes, cylinders and prisms with their size ranging from 150mm to 450mm were tested in unaxial compression. Failure patterns and the effect of specimen shape and size on compressive strength of concrete were investigated. In addition, theoretical size effect models, such as the MSEL and MFSL were used to analyze the size effect of concrete strength. It is shown that for specimens tested in this study, the two models are both applicable to predicting the compressive strength of specimens in various sizes with a reasonably good accuracy.


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