scholarly journals PENGARUH WAKTU PENGANGKUTAN ADUKAN BETON KE TEMPAT PENGECORAN TERHADAP KEKUATAN TEKAN

2019 ◽  
Vol 1 (2) ◽  
pp. 155-162
Author(s):  
Helwiyah Zain
Keyword(s):  
Compressive Strength ◽  
Time Delay ◽  
Casting Process ◽  
Mixing Process ◽  
Normal Concrete ◽  
Cement Ratio ◽  
Group I ◽  
Concrete Quality ◽  
Long Time

There is still a lot of casting concrete implementation which is mixing location was far with the casting location, because the situation in the field there are many obstacles to implement it.  As a result, from the mixing place to a casting place take a long time, so long as transportation there is a process of hydration in the concrete, which can cause a decrease in the quality of the concrete. To determine the decreasing of concrete quality, the research conducted is to determine the effect of time between when the mixing process of the concrete to casting process. This study used 48 specimens were divided into two groups, namely 24 specimens using the time difference without rotation and 24 pieces again with rotation. Each specimen using the same water cement ratio (fas), namely 0.45. Each group was subdivided in 6 variations in the time between mixing and casting namely :. 0 minutes, 12 minutes, 24 minutes, 36 minutes, 48 minutes and 60 minutes witch each variation using 4 specimens. The result of compressive strength each specimen group, for group I (without rotation) is 348 kg / cm2 for 0 minutes, 342 kg / cm2 for 12 minutes, 333 kg / cm2 for 24 minutes, 322 kg / cm2 for 36 minutes, 310 kg / cm2 for 48 minutes, and 294 kg / cm2 for 60 minutes. For group II (with rotation) is: 338 kg / cm2 for 0 minutes, 336 kg / cm2 for 12 minutes, 333 kg / cm2 for 24 minutes, 329 kg / cm2 for 36 minutes, 324 kg / cm2 for 48 minutes , and 318 kg / cm2 for 60 minutes. The results showed that, for the concrete without rotation: compressive strength at 60-minute time delay decreased by 15.52% of normal concrete (0 minute delay), and to the mixing concrete with rotation, compressive strength on delay of 60 minutes decreased by 5.92 % of normal concrete (0 minute delay). These results indicate that the delay time without rotation the greater the loss quality of concrete.

scholarly journals Lightweight Concrete With Mixed Foam Agent, Polymer and Bonding to Reach 300 Kg/Cm²

2020 ◽  
Vol 3 (1) ◽  
pp. 55-63
Author(s):  
Siti Rukmayani Japar ◽  
Freedy Kurniawan
Keyword(s):  
Compressive Strength ◽  
Specific Gravity ◽  
Lightweight Concrete ◽  
Agent Technology ◽  
Efficiency Coefficient ◽  
Light Weight ◽  
Normal Concrete ◽  
Earthquake Effect ◽  
Concrete Quality

Lightweight concrete is very much developed because of its benefits that can reduce the weight of the building itself, so that the earthquake effect on buildings can be minimized. By using Foam Agent Technology, it will add air pores which can reduce the specific gravity of normal concrete. To achieve the K 300 Concrete Quality with Light Weight, the researchers added Polymer and Polymer and Bonding mixture to the Concrete mixture using Foam Agent technology. From the research conducted by researchers, it was found that Foam Agent is able to help concrete become lighter by 13%. This research was also able to obtain the optimum compressive strength results with a light weight, the Light Concrete study with the addition of Foam Agent, Polymer and Bonding with a quality of 267 kg / cm² or equivalent to Fc 22 with a weight of 1877 Kg / cm³ and an efficiency coefficient of 14% which is higher than normal Concrete K 300 with a magnitude of 13%.

scholarly journals Water-Cement-Density Ratio Law for the 28-Day Compressive Strength Prediction of Cement-Based Materials

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Siqi Li ◽  
Jinbo Yang ◽  
Peng Zhang
Keyword(s):  
Compressive Strength ◽  
Apparent Density ◽  
Density Ratio ◽  
Strength Prediction ◽  
Normal Concrete ◽  
Present Contribution ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Cement Based Materials ◽  
Foamed Concrete

In the present contribution, the water-cement-density ratio law for the standard curing 28-day compressive strength of cement-based materials including grout, normal concrete, ceramsite concrete, and foamed concrete is proposed. The standard curing 28-day compressive strength of different grouts, normal concrete, ceramsite concrete, and foamed concrete was tested. Simulations for Abrams’ law, Bolomey’s formula, and water-cement-density ratio law were carried out and compared. The water-cement-density ratio law illustrates better simulations for the prediction of the 28-day compressive strength of cement-based materials. The water-cement-density ratio law includes both the water-cement ratio and relative apparent density of the cement-based material. Relative apparent density of the cement-based material is an important one of all the factors determining the compressive strength of the cement-based material. The water-cement-density ratio law will be beneficial for the precise and generalized prediction of the 28-day standard curing compressive strength of cement-based materials.

scholarly journals Effect of Low Mixing Speed on the Properties of Prolonged Mixed Concrete

2020 ◽  
Vol 6 (8) ◽  
pp. 1581-1592
Author(s):  
Ahmed Mohamed Abd El-Motaal ◽  
Ahmed Abdel-Reheem ◽  
Mohamed Mahdy
Keyword(s):  
Compressive Strength ◽  
Mixing Time ◽  
Mixing Process ◽  
Mixing Speed ◽  
Chemical Admixtures ◽  
Mixing Parameters ◽  
Slump Flow ◽  
Long Time ◽  
Ready Mixed Concrete ◽  
Mixed Concrete

The mixing process of concrete consists of dispersing the constituent ingredients (i.e. cement, admixtures, sand, and gravel) in water to homogeneous and solid product. The properties of the final product depend on mixing parameters such as mixing time and mixing speed. Ready Mixed Concrete (RMC) should be mixed for a long time with limited speed until delivered to the working site. This long time depends on long transport distances and traffic conditions. The present study investigated the effects of long mixing time on the properties of concrete without any change in its proportions during the mixing process and the effects of using the chemical admixtures: super plasticizers and retarders on its effectiveness, using a drum batch mixer. It has two directions of rotation: one for mixing concrete and the other for discharging it. This research identified concrete mixtures with local available materials i.e. cement, sand as fine aggregates, dolomite as coarse aggregates, water and chemical admixtures. Mixtures were prepared with the same cement and water content with constant sand to dolomite ratio with different dosages of chemical admixtures. Chemical admixtures were used to keep concrete flow during mixing. Mixtures were prepared with low mixing speed 1rpm for identified long mixing times more than 90 minutes from adding water to other components Slump and compressive tests were used as measurement tools of fresh and hardened concrete Retempering with extra water or chemical admixtures was prevented through mixing, so mixtures were extracted without target slump value. Findings showed that low mixing speeds made mixtures more effective for long times, the exceeding mixing time led to minimize water to cement ratio due to reduction of water content, and there was an inverse relationship between slump flow and compressive strength in case of no re-tempering. Therefore, slump flow of mixtures decreased by time, but on the other hand, compressive strength enhanced i.e. stiffening took place. The present study proved that the properties of the final product depends on mixing parameters such as mixing time and mixing speed, and that Ready Mixed Concrete (RMC) would be more effective if mixed for a long time with limited speed until transported to the work site. In addition, chemical admixtures with prolonged mixed concrete should be used to improve workability rather than compressive strength.

scholarly journals PEMANFAATAN LIMBAH GYPSUM BOARD DAN BATU BATA MERAH UNTUK SUBSTITUSI SEMEN PADA PEMBUATAN BETON

2019 ◽  
Vol 2 (2) ◽  
pp. 333
Author(s):  
Didik Hadi Prayogo ◽  
Ahmad Ridwan ◽  
Sigit Winarto
Keyword(s):  
Compressive Strength ◽  
Building Blocks ◽  
New Materials ◽  
Concrete Compressive Strength ◽  
Gypsum Board ◽  
Normal Concrete ◽  
Compressive Strength Test ◽  
Average Compressive Strength ◽  
Main Material

Concrete is one of the most vital building blocks, from columns, bricks, paving to roads made of concrete, so the use of concrete tends to be high. Concrete is often used as the main buffer in a building, so good quality is needed, but this is not accompanied by a declining quality of the material, so it requires innovation in the addition of new materials that can at least reduce the needs of the main material for making concrete, one of which is the utilization of Gypsum Board waste and red brick waste. The results of testing the concrete compressive strength test with the addition of Gypsum Board waste and red brick waste to cement obtained pretty good results. Concrete, which has the highest average compressive strength than normal concrete, has concrete with a mixture of red brick and gypsum waste of 10% each with a compressive strength of 250.56 kg / cm², and which has the lowest compressive strength have concrete with a mixture of red bricks and gypsum waste 15% each with a compressive strength of 195.56 kg / cm².Beton merupakan salah satu unsur penyusun bangunan paling vital mulai dari kolom,bata, paving hingga jalan terbuat dari beton sehingga penggunaan beton cenderung tinggi. Beton sering digunakan sebagai bahan penyangga utama pada suatu bangunan maka diperlukan kualitas yang baik, namun hal tersebut tidak di sertai dengan kualitas bahan yang kian menurun,makadiperlukan inovasi penambahan bahan baru yang setidaknya dapat mengurangi kebutuhan bahan utama pembuat beton, salah satunya pemanfaatan limbah Gypsum Board dan limbah batu bata merah Hasil dari pengetesan uji kuat tekan beton dengan penambahan limbah Gypsum Board dan limbah batu bata merah terhadap semen didapatkanhasil yang cukup bagus Beton yang memiliki nilai kuat tekan rata-rata paling tinggi selain beton normal di miliki beton dengan campuran batu bata merah dan limbah gypsum masing-masing 10% dengan nilai kuat tekan sebesar 250,56 Kg/cm²,dan yang memiliki nilai kuat tekan paling rendah di miliki beton dengan campuran batu bata merah dan limbah gypsum masing-masing 15% dengan nilai kuat tekan 195,56 Kg/cm².

scholarly journals Evaluation of the Effects of Coarse Aggregate Sizes on Concrete Quality

2017 ◽  
Vol 2 (10) ◽  
pp. 1 ◽  
Author(s):  
Lawrence Echefulechukwu Obi
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Aggregate Size ◽  
Test Results ◽  
Construction Sites ◽  
Coarse Aggregates ◽  
Appreciable Increase ◽  
Concrete Production ◽  
Concrete Quality

This work was necessitated by the observations made at construction sites where artisans and craftsmen were left alone in concrete production. It was discovered that they used inadequate quantity and size of coarse aggregates due to difficulty associated in the mixing as if the coarse aggregates were not needed in concrete production. The research has established that the coarse aggregates and their sizes play critical roles in the development of adequate strength in concrete. It was observed that with proper mixing, the slump test results did not witness shear or collapse type of slump rather there were true slump in all cases of the test. The workability decreased with slight differences when the coarse aggregate size was increased. The increase in the coarse aggregates yielded appreciable increase in the compressive strength. It can therefore be inferred that the quality of concrete in terms of strength can be enhanced through an increase in the coarse aggregate size when proper mix ratio, batching, mixing, transporting, placing and finishings are employed in concrete productions.

Correlation of Strength, Rubber Content, and Water-Cement Ratio in Roller Compacted Rubberized Concrete

2011 ◽  
Vol 243-249 ◽  
pp. 1179-1185
Author(s):  
Jing Fu Kang ◽  
Chun Xia Yan
Keyword(s):  
Compressive Strength ◽  
Test Results ◽  
Rubberized Concrete ◽  
Rubber Content ◽  
Normal Concrete ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Strength Based ◽  
Strength Formula ◽  
Cement Strength

This research investigated the influences of rubber content and water-cement ratio on the compressive strength of roller compacted rubberized concrete (RCR). The mix design of RCR was made by replacing same volume of sand with rubber chips based on the control concrete mix. Four rubber contents (50 kg/m3, 80 kg/m3, 100 kg/m3 and 120 kg/m3) and six water-cement ratios (0.30, 0.35, 0.40, 0.45, 0.50 and 0.55) were used. The specimen cubes were tested in compression at 28d with the load continuously and automatically measured until failure. Test results show that RCR exhibits low compressive strength but a ductile and plastic failure mode, the more the rubber used, the more the compressive strength reduced and the larger toughness obtained. Same as normal concrete, the compressive strength of RCR is also directly related to the water-cement ratio，the smaller the water-cement ratio, the higher the compressive strength. Based on the experimental results, a strength formula was developed to estimate the strength of RCR as a function of the cement strength, water-cement ratio and the rubber content.

scholarly journals PENGARUH PENAMBAHAN SILICA FUME DAN GLENIUM SKY TERHADAP KUAT TEKAN BETON K-400

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Sudirman Kimi ◽  
Abdullah Abuzar Alghafari
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
Test Object ◽  
Building Construction ◽  
Raw Material ◽  
Concrete Technology ◽  
Normal Concrete ◽  
Three Stages ◽  
Compressive Strength Of Concrete

In the development of concrete technology (Concrete Technology) today which is increasingly unceasingly, along with the development of the era hence the quality of concrete selection as the main raw material of building construction is very important. This research writer take silica fume and glenium sky as added concrete mixture to know the influence of the addition of silica fume and glenium sky to the compressive strength of concrete. The research is divided into three stages : material testing, test object making and test object. This research uses cube-shaped specimen with size 15x15x15 cm, with 5 variations, they are normal concrete, silica fume 5%, silica fume 5% + glenium sky 2%, silica fume 5% + glenium sky 4%, and silica fume 5% + glenium sky 6%, which every variations has 3 test specimens with 3 days, 7 days, and 28 days. From laboratorium testing, the characteristics of compressive strength of concrete at age 28 days of normal concrete is 407,2 Kg/Cm2, normal concrete with silica fume 5% is 418,5 Kg/Cm2, normal concrete with silica fume 5% + glenium sky 2% is 435,9 Kg/Cm2, normal concrete with silica fume 5% + glenium sky 4% is 451,9 Kg/Cm2, normal concrete with silica fume 5% + glenium sky 6% is 484,1 Kg/Cm2.

scholarly journals Pengaruh Cangkang Kerang Laut Terhadap Kuat Tekan Beton

2021 ◽  
Vol 2 (1) ◽  
pp. 46-54
Author(s):  
Neti Rahmawati ◽  
Irwan Lakawa ◽  
Sulaiman Sulaiman
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Building Materials ◽  
Coarse Aggregate ◽  
Fine Aggregate ◽  
Fine Aggregates ◽  
Concrete Quality ◽  
Compressive Strength Of Concrete ◽  
Physical Construction

Concrete is one of the most widely used building materials today interms of physical construction. Concrete is made from a mixture offine, coarse aggregate, cement, and water with a certain ratio, aswell as materials that are usually added to the concrete mixtureduring or during mixing, to changing the properties of concrete tomake it more suitable in certain jobs and more economical, can alsobe added with certain other mixed materials as needed if deemednecessary. Seashells can be used to mix concrete. This study aims todetermine whether the addition of shells aggregate shells in aconcrete mixture can affect the mechanical properties of concrete.The specimens used are in the form of cubes with a size of 15cm x 15cm x 15 cm, consisting of additional concrete coarse and fineaggregate with shell substitution percentage of 0%, 15%, 20% with atotal sample of 45, with the planned concrete quality of K225. Theuse of sea shells in increasing the compressive strength of concrete isbetter used as fine aggregate than coarse aggregate. The use of seashells as a substitute for fine aggregates achieves maximum resultsat 20% composition.

scholarly journals TINJAUAN HUBUNGAN KUAT TEKAN DAN LENTUR BETON DENGAN BAHAN TAMBAH SERAT BAJA UNTUK PERKERASAN PAKU

2019 ◽  
Vol 3 (1) ◽  
pp. 1-5
Author(s):  
Hermansyah Hermansyah ◽  
Muhammad Fauzie Siswanto ◽  
Ashar Saputra
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Steel Fiber ◽  
Concrete Mixture ◽  
Director General ◽  
Normal Concrete ◽  
Rigid Pavement ◽  
Concrete Quality ◽  
Relationship Of ◽  
The Relationship

The Director General of Highways issued the 2010 revision 3 specification concerning minimum flexural strength for rigid pavement of 45 kg/cm2 or approximately 4.5 MPa, but the reality of obtaining such flexural strength should be using  high enough concrete quality and it will incur considerably high cost also. In this study was using a normal concrete method with the purpose of research to know  the relationship of compressive strength and flexural of concrete with the addition of variation of fiber 0%, 0,5%, 0,65% and 0,8% from weight of the concrete mixture. The results from this research showed that the compressive strength and flexure had increased successively in the fiber variation 0%, 0.5% and 0.65% amount 31.23 MPa, 33.06 MPa, 35.23 MPa and 4.58 MPa, 4.75 MPa, 5.04 MPa. It is because the fiber contained in the concrete has a fairly even distribution of fiber and does not have clumping. When variations of fiber above 0.65% such as 0.8% variation in the direction of fiber are difficult to control and at the time of mixing occurs clumping, So the value of compressive strength and flexural of concrete are decreases. The relation of compressive strength and flexural of concrete using a variation of steel fiber to obtain equation fs = 0,1226.fc '+ 0,7173 with value R2 = 0,9915 and α 0,82. The results obtained from the test is a rather good when compared with ACI and SNI T- 15-1991-03 method.

scholarly journals OPTIMIZING THE USE OF ROCK ASH AS FINE AGGREGATES WITH THE ADDITION OF ADDITIVES TO THE CONCRETE MIXTURE WITH A COMPRESSIVE STRENGTH OF 350 Kg/cm2

CI-TECH ◽  
2020 ◽  
Vol 1 (01) ◽  
pp. 45-48
Author(s):  
Triaswati ◽  
Srie Subekti ◽  
Sulchan Arifin ◽  
Febri Aditya
Keyword(s):  
Compressive Strength ◽  
Test Object ◽  
Concrete Mixture ◽  
Normal Concrete ◽  
Type D ◽  
Cylinder Test ◽  
Fine Aggregates ◽  
Stone Dust ◽  
Compressive Strength Of Concrete

Stone dust nowadays is a side product of the stone crushing industry, the quality of which is quite a lot that it becomes a waste that needs to be handled. This study is intended to find out the composition of stone dust by adding some additive substance type D and type F to reach a compressive strength of 350 kg/cm2. The variation of percentage of stone dust on the composition of concrete mixture is 0%, 20%, 40%, 60%, 80%, 100%. The design of concrete mixture composition refers to the procedure of making preparation of the normal concrete mixture. SNI 03-2384-1993. The size of the cylinder test object is 15 cm in diameter and 30 cm in height. The result of this research shows that the mixture using stone dust has quite an effect on the compressive strength of concrete. From the result of the experiment, it is shown that for compressive strength of 350 kg/cm2, we can use 100% of stone dust with a resulted compressive strength of 445 kg/cm2.

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