Concrete compressive strength variation due to cement source change

2020 ◽  
pp. 1-20
Author(s):  
Jared L. Brown ◽  
Isaac L. Howard ◽  
Robert Varner
Keyword(s):  
Compressive Strength ◽  
Concrete Compressive Strength ◽  
Strength Variation

scholarly journals Compressive strength and grade of concrete in structures

2020 ◽  
Vol 23 (1) ◽  
pp. 27-35
Author(s):  
L.O. Zharko ◽  
V.P. Ovchar ◽  
V.H. Tarasyuk ◽  
О.А. Fesenko
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Point Of View ◽  
Concrete Compressive Strength ◽  
Economic Interests ◽  
Core Samples ◽  
Strength Variation ◽  
The Difference ◽  
Grade Assessment ◽  
The Relationship

The paper summarizes the experience of the Department of Buildings and Facilities Structures Research in determining the compressive strength and grade of concrete in the structures, which characterize one of the main requirements for ensuring the structures mechanical strength and stability. Their unambiguous interpretation at the stages of concrete composition selection, products manufacture and structures operation leads to a conflict of interests and corruption risks between a concrete producer, a builder and an investor. Two approaches to the concrete strength and grade assessment are considered: the first one reasons from the economic interests of a concrete producer (the possibility of cement saving at a stable well-organized production facility), the second one takes into account the consumer's point of view (design indicators ensuring). The first approach is based on the coefficient of the tested control concrete cubes strength variation declared by the concrete mixture manufacturer. The calculation of the relationship between the average and characteristic compressive resistance of concrete at various coefficients of concrete compressive strength variation and grades showed that this coefficient can significantly change the assessment results. The second approach is based on the use of reference core samples cut directly from the structure, which are tested and interpreted according to established international experience. The difference in strength assessments is shown for the cases with the use of samples tests results selection compared to groups in which the smallest values are removed. Both approaches are analyzed based on the experience of determining the concrete compressive strength grade using the core samples from the entire floor slab in the existing structure and from some its areas; the results were far from straightforward and not consistent with the project. It is necessary to clearly define the areas of application of norms and standards that, firstly, serve the technology and the production market of concrete and concrete and reinforced concrete products, and secondly, ensure obtaining the actual characteristics of existing products, structures and facilities and their conformity to the project. It is advisable, especially for the structures of the higher levels of responsibility and in some controversial matters, to verify the results obtained with the first approach application to the concrete mix test specimens by testing core samples cut from the structures.

scholarly journals PENGARUH PEMANFAATAN ABU PECAHAN TERUMBU KARANG DAN ABU SEKAM PADI SEBAGAI PENGGANTI SEMEN TERHADAP KUAT TEKAN BETON

2019 ◽  
Vol 11 (2) ◽  
pp. 12-16
Author(s):  
Yuzuar Afrizal ◽  
Nuzhi Ramahayati ◽  
Mukhlis Islam
Keyword(s):  
Compressive Strength ◽  
Coral Reefs ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Percentage Increase ◽  
Concrete Compressive Strength ◽  
Maximum Increase ◽  
Strength Variation ◽  
Local Material ◽  
Material Utilization

Portland cement is a relatively expensive type of cement when used on constructions requiring simple requirements. Local material utilization using ash fragments of coral reefs and rice husk ash is one of the solutions. The objectives of this study is to determine the value of concrete compressive strength in each variation of cement replacement used were 2.5%, 5%, 7.5% and 10%, each variation consists of 70% ash fragment of coral reefs and 30% rice husk ash from the volume of cement used. The cube specimen with a size of (15x15x15) cm as many as 20 specimen were prepared. Concrete mixture according to SNI 03-2834-2000 used 0.5 cement water ratio and 60-100 mm of slump. The result of the compressive strength of concrete variation every percentage increase has increased and decreased from the result of the normal concrete compressive strength of 368.24 kg/cm2. Maximum increase occurred in the concrete compressive strength variation 7.5% of 384.76 kg/cm2 and decreased on the concrete compressive strength variation 10% of 367.40 kg/cm2.

scholarly journals Compressive strength and grade of concrete in structures

2020 ◽  
Vol 23 (1) ◽  
pp. 27-35
Author(s):  
L.O. Zharko ◽  
V.P. Ovchar ◽  
V.H. Tarasyuk ◽  
О.А. Fesenko
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Point Of View ◽  
Concrete Compressive Strength ◽  
Economic Interests ◽  
Core Samples ◽  
Strength Variation ◽  
The Difference ◽  
Grade Assessment ◽  
The Relationship

The paper summarizes the experience of the Department of Buildings and Facilities Structures Research in determining the compressive strength and grade of concrete in the structures, which characterize one of the main requirements for ensuring the structures mechanical strength and stability. Their unambiguous interpretation at the stages of concrete composition selection, products manufacture and structures operation leads to a conflict of interests and corruption risks between a concrete producer, a builder and an investor. Two approaches to the concrete strength and grade assessment are considered: the first one reasons from the economic interests of a concrete producer (the possibility of cement saving at a stable well-organized production facility), the second one takes into account the consumer's point of view (design indicators ensuring). The first approach is based on the coefficient of the tested control concrete cubes strength variation declared by the concrete mixture manufacturer. The calculation of the relationship between the average and characteristic compressive resistance of concrete at various coefficients of concrete compressive strength variation and grades showed that this coefficient can significantly change the assessment results. The second approach is based on the use of reference core samples cut directly from the structure, which are tested and interpreted according to established international experience. The difference in strength assessments is shown for the cases with the use of samples tests results selection compared to groups in which the smallest values are removed. Both approaches are analyzed based on the experience of determining the concrete compressive strength grade using the core samples from the entire floor slab in the existing structure and from some its areas; the results were far from straightforward and not consistent with the project. It is necessary to clearly define the areas of application of norms and standards that, firstly, serve the technology and the production market of concrete and concrete and reinforced concrete products, and secondly, ensure obtaining the actual characteristics of existing products, structures and facilities and their conformity to the project. It is advisable, especially for the structures of the higher levels of responsibility and in some controversial matters, to verify the results obtained with the first approach application to the concrete mix test specimens by testing core samples cut from the structures.

Variasi Penambahan Sika Cim Dan Fiber Kawat Pada Beton Mutu Fc’ 30 Mpa

2018 ◽  
Vol 9 (2) ◽  
pp. 67-73
Author(s):  
M Zainul Arifin
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Curing Temperature ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Normal Concrete ◽  
Astm Method ◽  
Additive Type ◽  
Composition Variation ◽  
Compressive Strength Of Concrete

This research was conducted to determine the value of the highest compressive strength from the ratio of normal concrete to normal concrete plus additive types of Sika Cim with a composition variation of 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1 , 50% and 1.75% of the weight of cement besides that in this study also aims to find the highest tensile strength from the ratio of normal concrete to normal concrete in the mixture of sika cim composition at the highest compressive strength above and after that added fiber wire with a size diameter of 1 mm in length 100 mm with a ratio of 1% of material weight. The concrete mix plan was calculated using the ASTM method, the matrial composition of the normal concrete mixture as follows, 314 kg / m3 cement, 789 kg / m3 sand, 1125 kg / m3 gravel and 189 liters / m3 of water at 10 cm slump, then normal concrete added variations of the composition of sika cim 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1.5%, 1.75% by weight of cement and fiber, the tests carried out were compressive strength of concrete and tensile strength of concrete, normal maintenance is soaked in fresh water for 28 days at 30oC. From the test results it was found that the normal concrete compressive strength at the age of 28 days was fc1 30 Mpa, the variation in the addition of the sika cim additive type mineral was achieved in composition 0.75% of the cement weight of fc1 40.2 Mpa 30C. Besides that the tensile strength test results were 28 days old with the addition of 1% fiber wire mineral to the weight of the material at a curing temperature of 30oC of 7.5%.

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.

scholarly journals Study on Influence of Range of Data in Concrete Compressive Strength with Respect to the Accuracy of Machine Learning with Linear Regression

2021 ◽  
Vol 11 (9) ◽  
pp. 3866
Author(s):  
Jun-Ryeol Park ◽  
Hye-Jin Lee ◽  
Keun-Hyeok Yang ◽  
Jung-Keun Kook ◽  
Sanghee Kim
Keyword(s):  
Machine Learning ◽  
Compressive Strength ◽  
Linear Regression ◽  
Coarse Aggregate ◽  
Learning Algorithm ◽  
Linear Regression Analysis ◽  
Aggregate Size ◽  
Training Dataset ◽  
Machine Learning Algorithm ◽  
Concrete Compressive Strength

This study aims to predict the compressive strength of concrete using a machine-learning algorithm with linear regression analysis and to evaluate its accuracy. The open-source software library TensorFlow was used to develop the machine-learning algorithm. In the machine-earning algorithm, a total of seven variables were set: water, cement, fly ash, blast furnace slag, sand, coarse aggregate, and coarse aggregate size. A total of 4297 concrete mixtures with measured compressive strengths were employed to train and testing the machine-learning algorithm. Of these, 70% were used for training, and 30% were utilized for verification. For verification, the research was conducted by classifying the mixtures into three cases: the case where the machine-learning algorithm was trained using all the data (Case-1), the case where the machine-learning algorithm was trained while maintaining the same number of training dataset for each strength range (Case-2), and the case where the machine-learning algorithm was trained after making the subcase of each strength range (Case-3). The results indicated that the error percentages of Case-1 and Case-2 did not differ significantly. The error percentage of Case-3 was far smaller than those of Case-1 and Case-2. Therefore, it was concluded that the range of training dataset of the concrete compressive strength is as important as the amount of training dataset for accurately predicting the concrete compressive strength using the machine-learning algorithm.

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