scholarly journals PENGARUH UKURAN DIAMETER LUBANG DALAM ARAH MEMANJANG TERHADAP KEKUATAN TEKAN BENDA UJI SILINDER BETON

2019 ◽  
Vol 3 (2) ◽  
pp. 31-38
Author(s):  
Helwiyah Zain

Design of buildings should pay attention to aspects; Strength, comfort, economics, and aesthetics. One aspect of the aesthetic that is often seen is the rain water pipeline from the roof to the channel on the ground. In order for this pipe is not be seen from the outside, it can be done by aasembling into thecore of the column so that it looks beautiful. To know the effect of hole in the column, need to do research. The aim of this research is to find out the influence of the variation of the size of the longitudinal aperture in the cylindrical specimen against the compressive strength of the concrete. The number of specimen  were 20 pieces, consisting of 15 pieces of specimens given pipe holes and 5 pieces are not given a hole (intact). Variations of hole size, namely: 2.5 cm, 5 cm and 7.5 cm. Each variation of hole size of specimen 5 pieces. Concrete mixture design is done based on ACI method. The specimens used in this research are cylindrical shape specimens with diameter 15 cm and height 30 cm. Testing of concrete compression done at age 28 days. The test of the specimen is carried out by giving the compression load slowly until the specimen failured. The test results obtained the compressive strength of the specimen without hole = 266.48 kg / cm2;  specimen with hole diameter 2.5 cm = 243,08 kg / cm2; specimen with hole diameter 5 cm = 226,22 kg / cm2; and specimen with hole diameter 7.5 cm = 190,13 kg / cm2. The results of this experiments show that the specimen with diameter of  hole 2.5 cm is 91% of the specimen without hole, the specimen with hole diameter 5 cm is 85% of the specimen without hole; and the specimen with hole diameter 7.5 cm is 71% of the specimen without hole. The results of this experimen show that the larger size of the hole in the column the smaller the compressive strength of the concrete compared to the specimen without holes.

2018 ◽  
Vol 24 (1) ◽  
pp. 71
Author(s):  
Widodo Kushartomo ◽  
Dewi Permata Sari

This study is describe about the mechanical properties of normal concrete by adding of marble flour based on the mixed plan made. The compressive strength of the planned test object fc '20.0 and fc' 30.0 MPa was prepared by using the ACI method. The addition of marble flour in a concrete mixture varies from 0%, 5%, 10%, 15%, 20% and 25% to the weight of the cement used. Concrete test specimens were made in the form of cylinders 15.0 cm in diameter, 30.0 cm in height and made in the form of concrete beams measuring 15.0 cm x 15.0 cm x 75.0 cm, the type of mechanical testing performed in the form of compressive strength tests on cylindrical specimen, split tensile strength test on cylindrical specimen and flexure test on beam specimen. Curing is done by immersion technique at 25ºC and the test is done when the concrete is 28 days old. The test results show that the addition of marble flour to the normal concrete mixture can increase its mechanical properties by 26% for compressive strength, 24% for split tensile strength, and 17% for flexural strength. 


2021 ◽  
Vol 3 (1) ◽  
pp. 58-63
Author(s):  
Dewi Setiawati ◽  
Bambang Jatmika ◽  
Muhammad Rizal Aditya

This study aims to determine the effects of nickel slag in the concrete mixture and on its compressive strength value. In this study, cylindrical specimen having 15cm diameter and 30cm height is used. We have used nickel slag as substitute of coarse aggregate in weight ratio of 25%, 50% & 100% respectively of coarse aggregate in sample. The ratio of concrete mixture used in this study is comprised of ratio 1:2:3 of cement, sand & gravel respectively. Compressive strength was used as a parameter for testing the samples in this study.             Test was performed using compression Testing machine, from the test results, the mean value of the average compressive strength of cylindrical concrete at the age of 3 days with a 25% variant nickel slag is 134.02 kg / cm2, 50% variant nickel slag is 165.76 kg / cm2, and 70% variant nickel slag is 148.92 kg / cm2, at age 7 days for the 25% is 219.61 kg / cm2, the 50% variant is 191.27 kg / cm2, and the 70% is 181.57 kg / cm2, while at the age of 28 days the 25% is 275.09 kg / cm2, the 50% iis equal to 296.28 kg / cm2, and the 70% is 225.37kg / cm2  


2018 ◽  
Vol 9 (2) ◽  
pp. 67-73
Author(s):  
M Zainul Arifin

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%.


2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Sudarmadi Sudarmadi

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.


2021 ◽  
Vol 11 (3) ◽  
pp. 1037
Author(s):  
Se-Jin Choi ◽  
Ji-Hwan Kim ◽  
Sung-Ho Bae ◽  
Tae-Gue Oh

In recent years, efforts to reduce greenhouse gas emissions have continued worldwide. In the construction industry, a large amount of CO2 is generated during the production of Portland cement, and various studies are being conducted to reduce the amount of cement and enable the use of cement substitutes. Ferronickel slag is a by-product generated by melting materials such as nickel ore and bituminous coal, which are used as raw materials to produce ferronickel at high temperatures. In this study, we investigated the fluidity, microhydration heat, compressive strength, drying shrinkage, and carbonation characteristics of a ternary cement mortar including ferronickel-slag powder and fly ash. According to the test results, the microhydration heat of the FA20FN00 sample was slightly higher than that of the FA00FN20 sample. The 28-day compressive strength of the FA20FN00 mix was approximately 39.6 MPa, which was higher than that of the other samples, whereas the compressive strength of the FA05FN15 mix including 15% of ferronickel-slag powder was approximately 11.6% lower than that of the FA20FN00 mix. The drying shrinkage of the FA20FN00 sample without ferronickel-slag powder was the highest after 56 days, whereas the FA00FN20 sample without fly ash showed the lowest shrinkage compared to the other mixes.


2018 ◽  
Vol 53 ◽  
pp. 04021
Author(s):  
SHAO Yong ◽  
LIU Xiao-li ◽  
ZHU Jin-jun

Industrial alkali slag is the discharge waste in the process of alkali production. About one million tons of alkali slag is discharged in China in one year. It is a burden on the environment, whether it is directly stacked or discharged into the sea. If we can realize the use of resources, it is a multi-pronged move, so alkali slag is used to improve solidified marine soft soil in this paper. The test results show that the alkali residue can effectively improve the engineering properties of marine soft soil. Among them, the unconfined compressive strength and compressive modulus are increased by about 10 times, and the void ratio and plasticity index can all reach the level of general clay. It shows that alkali slag has the potential to improve marine soft soil and can be popularized in engineering.


2011 ◽  
Vol 121-126 ◽  
pp. 126-131 ◽  
Author(s):  
Qing Lei Xu ◽  
Tao Meng ◽  
Miao Zhou Huang

In this paper, effects of nano-CaCO3 on compressive strength and Microstructure of high strength concrete in standard curing temperature(21±1°C) and low curing temperature(6.5±1°C) was studied. In order to improve the early strength of the concrete in low temperature, the early strength agent calcium nitrite was added into. Test results indicated that 0.5% dosage of nano-CaCO3 could inhibit the effect of calcium nitrite as early strength agent, but 1% and 2% dosage of nano-CaCO3 could improve the strength of the concrete by 13% and 18% in standard curing temperature and by 17% and 14% in low curing temperature at the age of 3days. According to the XRD spectrum, with the dosage up to 1% to 2%, nano-CaCO3 can change the orientation index significantly, leading to the improvement of strength of concrete both in standard curing temperature and low curing temperature.


2013 ◽  
Vol 328 ◽  
pp. 679-683
Author(s):  
Ge Li ◽  
Xian Qin Hou ◽  
Zhi Min Liu

By molecular dynamics method, the tensile processes of nanosingle crystal copper with the crack front existence hole were simulated, and the effect of different hole size on crack propagation mechanism was analyzed. The results indicate that as the hole position remain unchanged, the hole diameter was more bigger, the atomic staggered and the crack tip deactivation were more obvious under tensile loads caused more dislocation glide appeared, meanwhile the number of slide-line was more and the trend of crack branch extend to hole position was more obvious.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber.


2014 ◽  
Vol 567 ◽  
pp. 381-386 ◽  
Author(s):  
Nasir Shafiq ◽  
Muhd Fadhil Nuruddin ◽  
Ali Elheber Ahmed Elshekh ◽  
Ahmed Fathi Mohamed Salih

In order to improve the mechanical properties of high strength concrete, HSC, several studies have been conducted using fly ash, FA. Researchers have made it possible to achieve 100-150MPa high strength concrete. Despite the popularity of this FAHSC, there is a major shortcoming in that it becomes more brittle, resulting in less than 0.1% tensile strain. The main objective of this work was to evaluate the fresh and hardened properties of FAHSC utilizing chopped basalt fiber stands, CBFS, as an internal strengthening addition material. This was achieved through a series of experimental works using a 20% replacement of cement by FA together with various contents of CBFS. Test results of concrete mixes in the fresh state showed no segregation, homogeneousness during the mixing period and workability ranging from 60 to 110 mm. Early and long terms of compressive strength did not show any improvement by using CBFS; in fact, it decreased. This was partially substituted by the effect of FA. Whereas, the split and flexural strengths of FASHC were significantly improved with increasing the content of CBFS as well as the percentage of the split and flexural tensile strength to the compressive strength. Also, test results showed a progressive increase in the areas under the stress-strain curves of the FAHSC strains after the CBFS addition. Therefore, the brittleness and toughness of the FAHSC were enhanced and the pattern of failure moved from brittle failure to ductile collapse using CBFS. It can be considered that the CBFS is a suitable strengthening material to produce ductile FAHSC.


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