scholarly journals THE SUITABILITY OF SEAWATER ON CONCRETING IN THE NIGER – DELTA ZONE

2019 ◽  
pp. 39-48
Keyword(s):  
Compressive Strength ◽  
Niger Delta ◽  
Mathematical Theory ◽  
Regression Models ◽  
Cement Content ◽  
Suitable Condition ◽  
Maximum Level ◽  
Minimum Level ◽  
Concrete Compressive Strength ◽  
Factorial Regression

This study was carried out in order to determine the suitability or otherwise of seawater for concreting. The study was carried out using the Box-Wilson symmetric composite plan B3, comprising 15 experimental points with 3 levels of treatment each. In accordance with the principle of the mathematical theory of experiment, multi-factorial regression models were evolved. The cement content at maximum level[x1 (+), water content at the minimum level [x2 (-)] and retarding admixture at minimum level of treatment [x3(-)] proved to be the most suitable condition for concreting. The result as follows were; Concrete slump: 60mm, Concrete density: 2450g/cm3, Concrete compressive strength: 22.56N/mm2, 26.65N/mm2 and 30.09N/mm2 for 7days, 14days and 28 days, respectively.

EFFECTS OF REPLACING CEMENT BY DATE PALM TREES WASTES ON CONCRETE PERFORMANCE

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ahmad Salah Edeen Nassef ◽  
Kalifa Hamed AlMuqbali ◽  
Sheikha Mahmood Al Naqabi
Keyword(s):  
Compressive Strength ◽  
Date Palm ◽  
Cement Content ◽  
Concrete Strength ◽  
Palm Tree ◽  
Compression Tests ◽  
Tree Leaves ◽  
Concrete Compressive Strength ◽  
Sustainable Environment ◽  
Palm Trees

This paper was studying the effects of palm tree wastes on the behavior of the concrete to reduce cement content in the concrete to ensure a sustainable environment. Both fibers of palm tree and the ash of palm tree leaves are used in this study considering different percentages of palm tree wastes, which are replaced the cement, to investigate both of workability and strength of the concrete. Also, the combination of palm tree leaves ash and fibers of palm trees is investigated. The slump and compression tests are carried out to evaluate both workability and concrete strength. The palm fibers were reducing the workability of concrete at both of different percentage of replacement and different fiber lengths. The slump is reduced by 26.667% at 2 cm fibers length and it is completely lost at 5 cm length fibers at the same percentage of replacement of 5% of the cement content. The palm fibers were weakening concrete compressive strength at different percentages and different fiber lengths. Palm leaves ash was enhancing concrete workability and concrete compressive strength.

Effect of coarse aggregate size on strength and workability of concrete

2006 ◽  
Vol 33 (2) ◽  
pp. 206-213 ◽  
Author(s):  
Peter J Tumidajski ◽  
B Gong
Keyword(s):  
Compressive Strength ◽  
Water Demand ◽  
Coarse Aggregate ◽  
Cement Content ◽  
Aggregate Size ◽  
Concrete Compressive Strength ◽  
Aggregate Fraction ◽  
Maximum Compressive Strength

The properties of concrete were studied when the proportions of 37.5 and 19.5 mm stone in the coarse aggregate were varied. With the cement content of 160 kg/m3 and the ratio of water/cement (w/c) greater than 0.9, the compressive strength is maximum at 25 percent by weight (w/o) of 37.5 mm stone. Conversely, for the cement content of 350 kg/m3 and w/c ratios of less than 0.50, maximum compressive strength is substantively reduced. For both 160 kg/m3 and 350 kg/m3 cement contents, workability improves slightly as the proportion of the 37.5 mm stone is increased. For 100 mm fixed slumps and cement content of less than 160 kg/m3, there was little change in compressive strength as the proportion of 37.5 mm stone increased. However, when cement content was increased from 190 to 350 kg/m3, maximum compressive strength was observed, which shifted downward from 50 w/o to 25 w/o of 37.5 mm stone. In general, to maintain a 100 mm slump, water demand decreased as the proportion of 37.5 mm stone in the coarse aggregate fraction increased.Key words: concrete, compressive strength, workability, slump, aggregate, size, cement.

scholarly journals Influence of Different Nano Materials on Mechanical Properties of Plain Concrete

2019 ◽  
Vol 4 (6) ◽  
pp. 129-134
Author(s):  
Mohamad Farouk Abd-elmagied
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Iron Oxide ◽  
Cement Content ◽  
Plain Concrete ◽  
Nano Materials ◽  
Nano Silica ◽  
Concrete Compressive Strength ◽  
Concrete Mix ◽  
Different Types

This research aims to study the influences of three types of Nano materials on concrete compressive strength, considered Nano types were Nano-Iron Oxide Fe2O3 (NF), Nano-Manganese Oxide Mn2O3 (NM), and Nano-Silica SiO2 (NS). A constant concrete mix and water content were considered. The used percentages of different types of (NF, NM, and NS) that replaced by the cement content were (0.5, 1.0, 2.0, and 5.0%) of mixture weight (wt). The results demonstrated that the (NS) Nano type has better effect than other types on the concrete compressive strength.

scholarly journals Tinjauan Ulang Mengenai Kadar Maksimum Pipih dan Memanjang Agregat Kasar dalam Campuran Beton Cara SNI. (Hal. 107-115)

2019 ◽  
Vol 5 (2) ◽  
pp. 107
Author(s):  
Decka Chaniago Sukanli ◽  
Priyanto Saelan
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Cylindrical Specimen ◽  
Maximum Level ◽  
Strength Test ◽  
Concrete Mixture ◽  
Concrete Compressive Strength ◽  
Slump Test ◽  
Coarse Aggregates ◽  
Compressive Strength Test

ABSTRAKDalam campuran beton, agregat kasar memiliki 70% sampai 80% pengaruh terhadap kuat tekan beton. Agregat kasar memiliki bentuk yang berbeda seperti membulat, pipih, dan memanjang tergantung pada sumbernya. Dalam penelitian ini, dilakukan penyelidikan pada kadar maksimum bentuk pipih dan memanjang agregat kasar dalam campuran beton. Pada penelitian kadar bentuk pipih dan memanjang agregat kasar ini menggunakan benda uji silinder dengan ukuran diameter 10 cm dan tinggi 20 cm. Pengujian dilakukan dengan uji slump dan uji kuat tekan beton yang mengacu pada SNI. Slump rencana yang digunakan yaitu (30-60) mm dan (60-180) mm dengan kuat tekan beton rencana yaitu 30 MPa usia 28 hari. Hasil pengujian ini dapat diketahui bahwa kadar pipih dan memanjang agregat kasar melebihi 20% tidak berpengaruh terhadap kuat tekan beton selama kadar pipih dan memanjang agregat kasar tidak melebihi 45% dari total agregat batu pecah.Kata kunci: bentuk pipih dan memanjang, agregat kasar, kuat tekan beton, uji slump ABSTRACTIn concrete mixture, coarse aggregate has 70% to 80% influence on concrete compressive strength. The coarse aggregate have different shape like rounded, angular, flaky and elongated depending on the source. In this study, we investigated the maximum level of flat and elongated coarse aggregate in concrete mixture. In the study of the level of flat and elongated forms coarse aggregates using cylindrical specimen with a diameter of 10 cm and a height of 20 cm. Testing was conducted with slump and concrete compressive strength test which refers to SNI. The slump plan used is (30-60) mm and (60-180) mm with a 30 MPa concrete compressive strength of 28 days. The results of this test can be seen that the flat and elongated of coarse aggregates exceeding 20% does not effect compressive strength of the concrete as long as the flat and elongated of coarse aggregates not exceed at 45% of the total aggregates.Keywords: flat and elongated shape, coarse aggregates, compressive strength, slump test

scholarly journals Frost resistance of concrete with crushed brick as aggregate

2010 ◽  
Vol 8 (2) ◽  
pp. 155-162 ◽  
Author(s):  
Ksenija Jankovic ◽  
Dragan Bojovic ◽  
Dragan Nikolic ◽  
Ljiljana Loncar ◽  
Zoran Romakov
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Compressive Strength ◽  
Experimental Research ◽  
Experimental Work ◽  
Frost Resistance ◽  
Cement Content ◽  
Recycled Concrete ◽  
Concrete Compressive Strength ◽  
Crushed Brick

The investigation included concrete made by using recycled brick as aggregate. Experimental work included several types of concrete made with the same cement content (385 kg/m3), and same consistency (slump about 1 cm). Recycled brick and combination of natural river aggregate and recycled brick were used as aggregates. The influence of percentage and grain size of crushed brick aggregate on concrete compressive strength, water absorption and frost resistance were observed. On the basis of the results obtained during experimental research, a general conclusion can be drawn that the application of recycled concrete as aggregate can lead to new composites with satisfactory physical-mechanical properties.

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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