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Expansive clay soil is soil that can expand and contract significantly in response to changes in soil moisture content. This study used an experimental method to stabilize expansive clay soil using a mixture of gypsum waste powder, which was tested using the Atterberg test, the Unconfined Compression Strength test, and the California Bearing Ratio test with mixture variations of 0%, 10%, 20%, and 30%. The results showed that the addition of gypsum waste powder could reduce the expansivity level of the soil from a very high level of 42% to a moderate level of 20%, increase the value in the Unconfined test at a maximum mixture of 10%, and increase the value in the CBR test at a maximum mixture of 30%. Based on the above description, this study aims to determine the extent of the effect of gypsum waste powder on expansive clay soil on the bearing capacity and compressive strength of expansive clay soil.

Beton sebagai material utama konstruksi sering mengalami panas hidrasi yang menyebabkan perbedaan suhu permukaan dengan suhu inti, akan berpotensi retak dini dan penurunan kuat tekan. Penelitian ini menganalisis potensi air es dan fly ash 10% substitusi semen untuk memperkecil suhu beton mutu 35 MPa dengan aditif tipe D (retarder) dan F (superplasticizer), serta pengaruhnya terhadap kuat tekan. Metode deskriptif menggunakan data sekunder mix design tiga variasi: non fly ash, fly ash 10% dan fly ash 10%+air es 10°C. Suhu beton segar diukur dengan thermogun/thermometer lalu kuat tekan uji silinder diameter 150x300 mm umur 7 hari dan 28 hari dengan total 18 benda uji. Hasil menunjukkan suhu beton segar non fly ash berada pada rentang normal, beton fly ash 10% turun 1-2°C (reaksi pozzolanik lambat yang mengurangi panas hidrasi dari C2S, C3S, dan C3A), beton fly ash 10% + air es turun 5-6°C. Kuat tekan 7 hari menunjukkan beton non fly ash 33,69 MPa, beton fly ash 10% 34,14 MPa, beton fly ash 10%+air es 34,73 MPa. Pada umur 28 hari menunjukkan beton non fly ash 39,73 MPa, beton fly ash 10% 39,80 MPa, dan beton fly ash 10%+air es 39,65 MPa – semua melebihi mutu rencana.

Beton merupakan material utama konstruksi yang masih memiliki kelemahan pada kuat tekan dan permeabilitas. Inovasi dengan penambahan Superplasticizer diharapkan mampu meningkatkan kualitas beton. Permasalahan penelitian ini adalah bagaimana pengaruh variasi dosis Superplasticizer (1%, 1,5%, dan 2% dari berat semen) terhadap kuat tekan dan permeabilitas beton dibandingkan beton normal. Penelitian ini menggunakan metode eksperimen dengan membuat 48 sampel beton silinder dan kubus yang diuji kuat tekan pada umur 7, 14, dan 28 hari serta permeabilitas pada umur 28 hari. Hasil penelitian menunjukkan bahwa penambahan Superplasticizer mampu meningkatkan kuat tekan dan menurunkan permeabilitas, sehingga dapat menghasilkan beton yang lebih kuat, kedap air, dan tahan lama.

Pengukuran deformasi yang akurat pada struktur beton dibawah pembebanan sangat penting untuk mengevaluasi kinerja dan daya tahan elemen-elemen tersebut. Ada beberapa keterbatasan dalam mengevaluasi struktur beton secara konversional seperti memerlukan waktu dan biaya besar. Beberapa penelitian menunjukan potensi fotogrametri jarak dekat dan pemodelan tiga dimensi (3D) mampu menganalisa deformasi, tegangan/regangan internal, dan perambatan retak. Penelitian ini mengusulkan metode pengukuran deformasi dengan empat tahapan untuk mengembangkan model 3D beton dengan menggunakan teknik fotogrametri jarak dekat dan selanjutnya pengolahan gambar. Tahapan metode yang digunakan: 1) mempersiapkan perangkat uji dan persiapan beton, 2) akuisisi gambar beton menggunakan kamera sebelum pengujian kuat tekan, menguji kuat tekan beton dibawah pembebanan, kemudian akuisisi gambar setelah pengujian kuat tekan beton, 3) melakukan pengolahan untuk menghasilkan model 3D beton, dan 4) membandingkan hasil model 3D sebelum dan sesudah pengujian kuat tekan beton. Untuk deformasi terkecil berapa pada sample beton 2 dengan loss volume sebesar 4%. Sementara itu, untuk deformasi terkecil berapa pada sample beton 3 dengan loss volume sebesar 26% yang menunjukan kuat tekan beton optimum berapa pada sample beton 2.

The use of sengon albasia ash waste as a partial cement substitute in concrete production is carried out to reduce combustion waste and also reduce cement use. This study focuses on the use of sengon albasia wood ash waste. The use of sengon albasia wood ash as a cement substitute causes a significant decrease in the slump test value. The use of sengon albasia wood ash as a partial cement substitute in concrete mixes actually produces different results depending on the proportion. If added as much as 10%, the concrete's compressive strength actually increases, but if it reaches 20% or 30%, the compressive strength actually decreases. This occurs because this type of wood ash has a significant water absorption capacity. As a result, the water that should be used for The chemical activity occurring between cement and water is diminished, so that the bond between the cement mixture as a binder and aggregate as a filler is reduced, and ultimately the concrete's compressive strength also decreases.

Penelitian ini bertujuan untuk mengetahui berat beton, kuat tekan dan nilai biaya pada beton campuran styrofoam sebagai pengganti agregat kasar untuk mendapatkan beton ringan dengan cara membuat benda uji berbentuk silinder Ø15-30 cm dengan perbandingan volume 1 Pc: 2 Pasir: 3 Styrofoam, 1 Pc : 1.5 Pasir: 2, 5 Styrofoam dan 1 Pc : 1,25 Pasir : 2,75 Styrofoam serta beton normal dengan komposisi 1 Pc : 2 Pasir dan 3 Agregat kasar sebagai pembanding. Berat volume yang diperoleh untuk komposisi 1 Pc: 2 Pasir: 3 Styrofoam adalah 1323,64 kg/m3,komposisi 1 Pc: 1,5 Pasir: 2,5 Styrofoam adalah 1274,61 kg/m3,dan komposisi 1 Pc : 1,25 Pasir : 2,75 Styrofoam adalah 1112,46 kg/m3, dan beton normal 1 Pc : 2 Pasir : 3 Kerikil adalah 2366,33 kg/m3. Selisih berat beton styrofoam terhadap beton normal kurang lebih 47,73%. Kuat tekan karakteristik komposisi 1 Pc: 1,5 Pasir: 2,5 Styrofoam 85,73 kg/cm2, 1 Pc: 1,25 Pasir: 2,75 Styrofoam 80,39 kg/cm2 sedangkan kuat tekan karakteristik untuk komposisi 1 Pc: 2 Pasir: 3 Styrofoam adalah 110,31 kg/cm2 (>100 kg/cm2) dan beton normal 1 Pc : 2 Pasir : 3 Kerikil adalah 155,29 kg/cm2. Berat volume beton  campuran styrofoam dan karakteristik kuat tekan menunjukkan bahwa styrofoam sebagai pengganti agregat kasar hanya ditujukan untuk pekerjaan konstruksi ringan. Biaya pembuatan beton komposisi 1 Pc: 2 Pasir: 3 Styrofoam adalah Rp. 1.751.365, 1 Pc: 1,5 Pasir: 2,5 Styrofoam sebesar Rp. 1.555.587, dan komposisi 1 Pc : 1,25 Pasir : 2,75 Styrofoam sebesar Rp. 1,604,697, sedangkan untuk beton normal 1 Pc : 2 Pasir : 3 Kerikil hanya sebesar Rp. 631,293. Selisih perbandingan biaya beton campuran styrofoam lebih mahal kisaran 63,95% dari harga beton normal.

This research was conducted to analyze the performance of the extruder machine on the production quantity and quality of bricks. Analysis shows that the engine transmission uses a type B belt with a belt circumference of 1063.622 mm, so the v belt used by the motorbike has a nominal belt number of 41 inches. From the results of the linear regression of red bricks before being burned with a correlation value of 98.7%, it can be categorized as very strong. The linear regression for red bricks before burning is 0.10 while alpha < 0.05 so it can be concluded that there is no significant influence on variables X and Y. The linear regression for red bricks after burning is 0.07 while alpha < 0.05 so It can be concluded that there is no significant influence on variables X and Y.

This research utilizes waste from PLTU Tanjung Jati B Jepara, namely FABA (Fly ash Bottom Ash) as an alternative to fine and coarse aggregate. From this research, the physical properties of faba aggregate can be seen from the results of the faba aggregate sieve analysis test, which obtained a fineness modulus value of 1.74, which is included in the medium aggregate type. The water content of fine aggregate (fly ash) obtained a value of 3.63% and coarse aggregate (bottom ash) obtained a value of 1.5%. The fine aggregate sludge content (fly ash) obtained a value of 0%. The fine aggregate organic substance (fly ash) acquires a reddish brown NaOH color, therefore it must be washed before being used as a concrete mixture. The face dry specific gravity of fine aggregate (fly ash) obtained a value of 2.63 gr/cm2 and coarse aggregate 2.52 gr/cm2. From the data that has been obtained, faba aggregate is considered to have physical properties that meet the requirements for fine aggregate and can be used as a substitute for sand. The results of the final compressive strength of faba concrete and normal concrete at the age of 7 days and 28 days showed that the compressive strength of normal concrete (control) was higher than that of faba concrete. The standard deviation values ​​at the ages of 7 and 28 days are included in perfect working conditions because they have a standard deviation value of less than 3 MPa. From the results of the concrete flexural strength test, only the control concrete was 1;1.5 with a flexural strength of 4.18 MPa, which is close to SNI 2847:2013, namely with a minimum flexural strength of fs = 4.4 MPa. Normal concrete has a higher flexural strength than faba concrete. Based on tests carried out with the planned mix design, the 1:1.5 variation obtained the highest results.

This research is an experimental study on porous concrete and the use of fly ash as a binder for concrete to analyze the effect of compressive strength and porosity. The research method used in this study is the experimental method which is a research method used to find the effect of certain treatments on concrete. In this research, the concrete mix design uses a ratio of gravel and geopolymer paste as a binder, namely 4: 1 and uses a molarity ratio of 10M with differences in grading of coarse aggregate using sieves number 4, 1/2 ", and 3/8". The optimum compressive strength value was obtained in mix design 1 using sieve gradation no.4 which was 4.25 MPa at 28 days old. While the results of the highest porosity value were found in mix design 1 which was 7.15% at 28 days old

Stabilisasi tanah merupakan upaya memperbaiki tanah dalam keadaan tertentu sehingga didapatkan karakteristik tanah yang diinginkan dengan menambah zat aditif untuk meningkatkan kekuatan tanah. Tujuan penelitian ini untuk mengetahui sifat fisis dan mekanis tanah asli, mengetahui pengaruh bahan stabilisasi tambahan terhadap tanah, dan perbandingan pada campuran optimal. Penelitian ini menggunakan bahan semen PCC dan semen instan. Metode yang digunakan dalam penelitian ini yaitu pengujian laboratorium dengan uji kuat tekan bebas (UCT) dengan masing masing bahan aditif menggunakan komposisi campuran 0%,4%,8% dan 12%. Berdasarkan pengujian sifat fisis tanah asli memperoleh nilai berat jenis rata rata 2,595, (γb) 1,637 gr/cm³, dan termasuk jenis tanah lempung organik dengan plastisitas sedang sampai tinggi (OH). Berdasarkan sifat mekanis diperoleh dengan uji UCT tanah asli memiliki nilai kuat tekan bebas 0,677 kg/cm2 dengan Cu yaitu 0,338 kg/cm2. Untuk kuat tekan bebas tanah asli dan semen PCC paling tinggi didapat 1,776 kg/cm2 pada komposisi bahan stabilisasi semen PCC sebesar 8%, dan kuat tekan tanah asli dan semen instan paling tinggi didapat sebesar 1,967 kg/cm2 pada campuran semen instan 8%. Berdasarkan penelitian dapat disimpukan bahan paling optimal yaitu semen instan dengan komposisi campuran 8%. Perbandingan kuat tekan bebas dari tanah asli dibandingkan dengan semen PCC dan semen instan yaitu 0,677; 1,776;1,967.

Parepare City is located on the coast with significant fisheries and maritime potential. The processing and consumption of shellfish in this city produces a lot of shellfish waste, which is often not utilized and accumulates into an environmental problem. To improve the properties of concrete, several types of additives that have certain functions are added to the concrete mixture, namely increasing the workability, durability, and hardening time of concrete. This study aims to determine the compressive strength of concrete and the composition of coarse aggregate of shells with superplasticizer added materials that are optimally produced. Using an experimental method carried out at the Laboratory of Structure and Materials, Muhammadiyah University of Parepare. The results showed that substitution of coarse aggregate with 5% shellfish waste and 0.5% superplasticizer increased the compressive strength of concrete at the ages of 7, 14, and 28 days. The 10% substitution still meets the compressive strength requirements at 28 days, although slightly lower than normal concrete. Substitution of shells up to 5% increases the compressive strength of concrete, and the 10% content is optimal, reaching the maximum value without significant decline. It is recommended that the use of shells as a substitute for coarse aggregate does not exceed 10% for optimal results and meets the planned compressive strength of 25 MPa.

Increased economic growth in the city of Parepare with the presence of buildings around the estuary. In general, the composition of concrete making materials is taken from good materials. The problem encountered in the field is that the quality of concrete in construction decreases due to brackish water, causing structural elements in the construction to become porous. Meanwhile, preventive measures are rarely or never taken. As a result, the construction life is very short. Brackish water is one of the causes of structural failure. This is due to the content of sulfate and chloride ions in water containing salt/salts that react with chemical elements in reinforcing steel resulting in corrosion of the reinforcement. The purpose of the study was to analyse the compressive strength of concrete with a mixture of clean water against the percentage of brackish water with a maintenance age of 7, 14, 21, and 28 days. The results showed that brackish water had an impact on reducing the compressive strength of concrete due to the high chemical content in brackish water such as Sulfate (SO²¯) of 52.5 in brackish water in Kenjeran and 62.5 in brackish water in mangrove. Dissolved Solids (TDS) of 15188 mg/l in kenjeran brackish water and 3436 mg/l in mangrove brackish water. Organic Content (KMnO) of 8.05 mg/l in kenjeran brackish water and 6.69 mg/l in mangrove brackish water is too high, so the chemical content contained in brackish water can damage the compounds in the cement content and decrease the strength of the materials contained in the concrete. In this case it can result in concrete having a very low durability.

In the process of designing mine slopes, drilling or tunneling, to determine the level of strength and brittleness factors of rock on a slope, it is necessary to carry out a uniaxial compressive strength test or indirect tensile strength test of the rock. Compressive strength testing is carried out to determine how long the rock maintains its strength or elastic properties when pressure is applied. This data can be used as information to understand the analysis of factors that influence the physical properties of rocks on the compressive strength of rocks from physical properties and compressive strength testing activities. and indirect tensile strength testing is carried out to determine the stress value contained in the rock. To determine the level of rock brittleness, it can be done by comparing the uniaxial compressive strength value and the indirect tensile strength value. This data can be used as information and reference for companies that will design a mine slope, drill and tunnel, how strong the strength and level of brittleness of rocks in areas dominated by sandstone. This research uses quantitative methods, so that to obtain accurate calculation data, testing methods are used in the form of uniaxial compressive strength tests and indirect tensile strength tests, in this case tested on sandstone samples obtained from 2 rock formations including the Pulaubalang formation and the Balikpapan formation, so that accuracy The test result values ​​can be obtained well. And after testing, a comparison is made between the uniaxial compressive strength test value and the indirect tensile strength test to obtain the Brittleness Index value.Based on the observation results, it can be concluded that when the brittleness of the rock becomes greater, the performance of the cutting digger increases several times.    

To determine the mineral content and composition of a rock, a petrographic test is carried out using a thin section method. Petrographic test is known as an efficient test of time and energy with accurate results in obtaining the composition and mineral content of rocks. The Point Load test is an index test that has been widely used to predict the UCS value of a rock indirectly in the field. This is due to the simple test procedure, easy sample preparation and can be done in the field, so that the strength of the rock can be quickly known in the field before testing in the laboratory.

Rock strength has an important role in the mining industry. These forces can determine many aspects of mining such as slope geometry, excavation, blasting, and drilling. Rock strength can include tensile strength, compressive strength, and shear strength. In this case, the test is carried out to determine the correlation of uniaxial compressive strength and indirect tensile strength. The method used to determine the correlation of compressive strength and indirect tensile strength is by linear regression approach, which will then be analyzed for accuracy through Root Mean Square Error (RMSE), and Mean Absolute Percentage error (MAPE). This study used quantitative and qualitative methods, starting from the coordinate data of rock sampling locations, physical properties and mechanical properties. In this study, there were 6 sampling locations located in 2 different areas, namely Loa Janan and Sanga-sanga. The secondary data used are regional geological maps and maps of the area where the study is located. Furthermore, secondary data is processed using Arcgis software for mapping, and using Microsoft Excel software to assist in calculations in determining the value of physical and mechanical properties of rocks. The results of the compressive and tensile strength tests in this study showed a perfect corelation using linear regression, namely UCS= 3.9582 σt - 0.4004, with a correlation coefficient (R) of 0.972 and a determination coefficient (R2) of 0.945. and obtained RMSE 0.033 and MAPE 5.89%.

Rock strength is the ability of a rock to maintain its strength until it breaks when a force is applied. Rock compressive strength is a very important parameter in the world of mining. The compressive strength of the rock determines the mining method that will be used. Several things that influence the compressive strength of rock include porosity, true specific gravity, and water content. With the same volume, if the porosity value is high, the true specific gravity value will be low because of the large number of pores in the rock. This allows the compressive strength value to be low because the rock will crumble more easily when pressure is applied. After testing, the highest compressive strength value was in the Pulaubalang Formation, location 2, with a value of 2.19 MPa. Meanwhile, the lowest compressive strength value was in the Kampungbaru Formation, location 1, with a value of 1.49 MPa. In accordance with the stratigraphic layers in the Kutai Basin, the Pulaubalang Formation is older than the Kampungbaru Formation.    

This research aims to determine the effect of adding the additive Sika Fume on the compressive strength of concrete. This research uses a type of quantitative research with experimental methods, namely by carrying out several tests on test objects in the laboratory. The results of this research show that the compressive strength of concrete with the addition of sika fume varies 0%, 3%, 5%, 7% and 8% of the cement weight, so the experimental results show that the average compressive strength at the age of 28 days of concrete has a variation of 0 % of 26.14 Mpa, 3% variation of 25.01 Mpa, 5% variation of 27.08 Mpa, 7% variation of 24.16 Mpa, 8% variation of 23.40 Mpa. The concrete compressive strength variation of 5% with an average of 27.08 Mpa is the variation with the highest compressive strength value and reaches the design compressive strength. Meanwhile, a variation of 8% with an average of 23.40 Mpa is the lowest compressive strength value and does not reach the design compressive strength.

Porous concrete has high porosity so that water can pass through the cavities in the concrete. The application of porous concrete is usually for parking areas, pedestrian sidewalks, road shoulders, drainage, roads with low traffic volume. Indonesia is an archipelagic country, most of Indonesia's territory is by the sea so it is very possible to use sea water as a substitute for fresh water for porous concrete. This research aims to determine the comparison of compressive strength of porous concrete mixed with sea water and normal porous concrete with variations in the water cement (fas) factor. In this study, a concrete mixture with a water cement (fas) factor of 0.30 and 0.35 was used. The test object used was a 15x30 cm cylindrical concrete test object for the compressive strength test. The test on porous concrete was carried out during the curing period of 28 days. The test results for the compressive strength of normal porous concrete with a water cement (fas) factor of 0.30 and 0.35 are 6.658 Mpa and 4.435 Mpa, then for porous concrete mixed with sea water with a water cement (fas) factor of 0.30 and 0, 35, namely 6,700 Mpa and 3,374 Mpa. The test results show that the sea water mixture in porous concrete does not affect the compressive strength of porous concrete, whereas the use of variations in the water cement factor (fas) shows that the compressive strength of porous concrete, both normal porous concrete and porous concrete mixed with sea water, has decreased. as the value of the water cement (fas) factor used increases.

PLTU produces coal-burning residues in the form of fly ash waste, which is constantly increasing. Fly ash is an industrial waste that is hazardous to the environment and human health but can be exploited because it has the characteristics of pozzolan. We conducted research on the use of fly ash as a cement substitute in the making of paving blocks. The aim of the research was to find out the strong pressure paving block method in British Standard 6717 with SNI 03-0691-1996 against the use of fly ash and how much of the fly ash is used against the strength of the optimum pressure. The research used an experimental method, with a comparison of 1 cement with 4 sand and variations in the use of air ash at 0%, 10%, 20%, and 30%. Tests were conducted when paving the block through the process of curing for 28 days. This study resulted in a strong average pressure paving block (PB) using the British Standard fly ash method 6717, with PB beam variations of 10%, 20%, and 30% in succession of 14.23 MPa, 13.49 MPa, and 11.14 MPa. While the SNI method 03-0691 1996 is PB cube variation at 10%, 20%, and 30%, respectively, of 12.27 MPa, 10.63 MPa, and 8.67 MPa. The strong result of pushing PB beams using the optimum fly ash is found at a 10% variation of 14.23 MPa and a 10% cubic variation PB of 12.27 MPa.

Concrete is a rock made from a mixture of cement, sand, aggregate and water. For this reason, this construction material is very important to develop. One effort to develop it is by utilizing industrial waste. Like other industrial waste, wood ash waste can also be used as a partial replacement for cement. The aim of this research is to determine the effect of adding wood ash as an additive to cement on the compressive strength and tensile strength of concrete, as well as to determine the effect of varying the percentage of wood ash in the concrete mixture on the compressive strength and split tensile strength of concrete. The type of research used in this research is quantitative research with experimental methods, namely by comparing normal concrete with 3 variations of mixture to determine the compressive strength and splitting tensile strength of the concrete. The results of the research showed that the experimental compressive strength and split tensile strength of concrete on normal concrete and variations of 3 mixtures, namely 2%, 4% and 6% of cement, obtained experimental results on the compressive strength of concrete for 28 days of normal concrete with an average of the average of 25,478 Mpa decreased with a 2% variation with an average of 24,723 Mpa, and decreased drastically for a 4% variation with an average of 19,439 Mpa, and for a 6% variation with an average of 18,967 MPa. Meanwhile, in testing the split tensile strength of normal concrete with an average of 7.185 Mpa, it experienced an increase from normal concrete with a variation of 2% with an average of 7.333 Mpa, and experienced a decrease from normal concrete with a variation of 4% with an average of 6.667 Mpa, and 6%. with an average of 6 Mpa. So it can be concluded that concrete with a variation of 2% wood ash does not really affect the compressive strength of the concrete, but the more wood ash that is added, the compressive strength of the concrete will decrease. From this research it can be concluded that the use of wood ash does not achieve the planned compressive strength so it is not suitable for use in construction.