Average Compressive Strength Value Research Articles

PENGARUH PENAMBAHAN SERAT BAMBU PADA PEMBUATAN PAVING BLOCK TERHADAP KUAT TEKAN

Bamboo is widely used for various forms of building construction, such as houses, as roofs, columns and foundations. Apart from that, the remainder of its use will become waste. One of the building materials that is often used is paving blocks as an alternative ground surface cover that can be used for road pavement, parking lots, pedestrians, parks, etc. The aim of this research was to determine the effect of adding bamboo fiber with variation of 1%, 3%, and 5% on the compressive strength of paving blocks. The method used in this research is the experimental method. Primary data consists of material testing results and paving block compressive strength. Research was conducted at the Structures and Materials Laboratory, Departement of Civil and Mining Engineering, Ketapang State Polytechnic. From the results of the compressive strength testing of paving blocks that have been carried out, the highest average value of compressive strength of paving blocks with a variation of 1% is 320.01 kg/cm2 which corresponds to the quality concrete C used for home garage pavement, pedestrian circulation, and parking lot.

PENGGUNAAN BAHAN ADITIF MASTER GLENIUM ACE 8595 UNTUK MEMINIMALISIR POROSITAS PADA BETON

<p><em>Concrete has now become the most essential material in modern construction. The strength and durability of concrete are vital factors that influence the strength and stability of buildings and infrastructure. Porosity refers to the degree to which concrete has voids or voids within its structure. Concrete porosity has a significant impact on concrete compressive strength. The higher the level of porosity, the lower the compressive strength of the concrete. In this research, we conducted a concrete formulation experiment by adding a type F additive to MasterGlenium Ace 8595. This research investigates the effect of adding the additive Master Glenium Ace 8595 on changes in concrete porosity and increasing concrete compressive strength. The results of the research show that from the aggregate suitability testing, it was stated that all the aggregates tested were suitable for use as a building material for concrete, workability testing obtained results with dilute criteria, porosity testing obtained an average porosity of 8.05%, and compressive strength testing obtained an average compressive strength value. -an average of 23.56 MPa indicates an increase of 8.69% of the planned concrete quality. This research concludes that concrete porosity is one of the factors that must be considered to increase the compressive strength of concrete because it significantly influences its density and compressive strength. Keeping the porosity at a low level and the compressive strength of the concrete at a high level can ensure that the concrete structure has good resistance to loads and the environment and reduces the risk of damage and maintenance.</em></p>

The effect of crystalline technology on concrete as coating to improve its durability

This research delves into the effects of incorporating Crystalline Additives (CAs) in concrete, specifically exploring alterations in compressive strength, water penetration resistance, and chemical durability when subjected to corrosive solutions, including H2SO4 and HCl. The investigation encompasses four concrete compositions: Standard Concrete, Concrete with Single Layer Crystalline Coating, Concrete with Double Layer Crystalline Coating, and Concrete featuring Type V Cement. Results indicate that the application of Crystalline coating contributes to notable enhancements in the average compressive strength, albeit falling short of the peak strength achieved with Type V cement. Notably, exposure to a 5% H2SO4 solution triggers more pronounced deterioration compared to exposure to 5% HCl, leading to discernible reductions in both weight and compressive strength. Despite Crystalline coating’s beneficial impact on compressive strength, it remains outperformed by the application of Type V Cement, as evidenced by superior average compressive strength values. Conversely, the efficacy of Crystalline coating in countering water penetration remains inconclusive, as evidenced by the water penetration test outcomes. This ambiguity underscores the necessity for further research to ascertain the true extent of Crystalline coating’s influence on water resistance.

Pengaruh Pemanfaatan Kulit Kerang Sebagai Pengganti Sebagian Agregat Halus dengan Menggunakan Pasir Pantai Terhadap Kuat Tekan Beton dan Mutu K-200

The influences of shells utilization as smooth aggregate replacement by using sands beach on the concrete compressive strength and the quality of k-200, the use of smooth aggregate substitutes, such as manually broken clam shells and beach sand obtained from Paciran, Lamongan Regency. The mixture used in making concrete is concrete with quality K-200 (fc'16.60 Mpa). Concrete sand will be replaced by 50% with beach sand, and mixed variations will be carried out with the addition of shells by 10%, 15%, and 20%. The test results show that the average compressive strength of normal concrete is 16.60 Mpa. For a mixture with shell waste by 10% and sea sand by 50%, the average compressive strength value is 15.09 Mpa. In a mixture with shell waste by 15% and sea sand by 50%, the average compressive strength value is 14.62 Mpa. While in a mixture with shellfish waste of 20% and sea sand of 50%, the average compressive strength value is 14.13 Mpa. The concrete variant with the highest average compressive strength value is the normal variant with a value of 16.60 Mpa, while the concrete variant with the lowest average compressive strength value is the variant with shell waste of 20% and sea sand of 50%, with a value of 14.13 Mpa.

Pengaruh Penggunaan Limbah Abu Arang Briket Dan Serbuk Batu Bata Merah Sebagai Pengganti Sebagian Semen

Concrete is defined as a mixture of its constituent materials consisting of hydraulic material (Portland Cement), coarse aggregate, fine aggregate and water, with or without the use of added materials (admixture or additives). Cement production produces waste that is harmful to the environment. Utilizing charcoal briquette ash waste and red brick powder waste is an alternative. In this study, 12 cylindrical test objects were used (15 cm x 30 cm) with the use of red brick powder and charcoal briquette ash as a partial replacement for cement plus 3 pieces of normal concrete of the same size without the use of partial cement replacement materials. Percentage of partial replacement of cement with red brick powder 2% briquetted charcoal ash 6% (BB2A6), red brick powder 2% briquetted charcoal ash 9% (BB2A9), red brick powder 2% briquetted charcoal ash 12% (BB2A12), and red brick powder 2% charcoal briquette ash 15% (BB2A15) to the weight of cement. From the research, the effect of using variations of 2% red brick powder and 6% charcoal briquette ash is the variation that has the largest average compressive strength value of 14.29 MPa of all variation.

Utilization of Steel Slag Waste as Construction Materials of Rigid Pavements

Roads play an important role in realizing the development and distribution of development results in certain areas. Pavement performance shows a decreased durability over time-related to how long the pavement construction can carry out its functions without experiencing fatal damage. This study aims to identify the effect of using steel slag as a substitute for filler with steel slag content of 0%, 1%, 2%, and 3% on concrete compressive and flexural strength values. This study used an experimental method by conducting experiments for testing the compressive and flexural strength of concrete specimens. The results showed that the use of steel slag as a substitute for filler obtained the average compressive strength value of MPa, 21.87 MPa, 22.17 MPa, and 28.47 MPa in concrete aged 28 days with steel slag content of 0%, 1%, 2% and 3% 25.07 respectively. The average flexural strength of concrete aged 28 days with steel slag content of 0%, 1%, 2% and 3% were 3.84 MPa, 2.83 MPa, 3.41 MPa, and 4.09 MPa respectively. The composition of 3% steel slag was the optimal composition as a filler replacement material. The pozzolanic properties of steel slag could increase the durability and density of the concrete specimen, but it required a long curing time and the increase in the initial strength of concrete slows down.

PENGARUH SUBSTITUSI CANGKANG KERANG DARI ENDE NTT TERHADAP KUAT TEKAN DANKUAT LENTUR BETON fc’= 19,3 MPa

The use of concrete for basic construction materials today is indeed increasing rapidly along with the development of construction construction.Only a concrete quality of 19.3 MPa (fc '= 25 MPa) was considered in this study. Since cement, aggregates, sand and water are extracted from nature, they must be limited. So in this study using additional material clam shells. One of them is shells, shellfish waste or shells are usually only used as decorations or toys so that there is still a lot of waste wasted. Inside the shell, the clam contains pozzolan chemical compounds, namely lime (CaO), aluminum oxide and silica. It can be expected to improve the quality of concrete.
 As a result of compressive strength test by changing the clamshell to 0%, 10%, 20%, 30%, 40% and 50%, the average compressive strength value of 0% (ordinary concrete) was 15.81 MPa. The addition of a 10% clam shell results in an average compressive strength value of 20.58 MPa. For the addition of clam shells by 20% obtained an average compressive strength value of 23.37 MPa. 30% yields an average compressive strength of 40.31 Mpa, to 40% of 29.12 Mpa. As for the addition of 50% clam shells, the average compressive strength value is 24.79 Mpa. Thus it can be concluded that the addition of clam shells 30% compressive strength value is higher than the compressive strength value of concrete with the addition of clam shells 0%, 10%, 20%, 40%, and 50%The flexural strength test value in terms of the maximum average moment on the beam for each variation of the test specimen is maximum moment value 75.02 kN.m for 0% variation, maximum moment value 62.52 kN.m for 10% variation, maximum moment value 68.77 kN.m for 20% variation, maximum moment value for 30% variation 62.52 kN.m, 40% variation at maximum moment value of 62.52 kN.m. Therefore, the percentage of specimens that can withstand the highest load in the flexural strength test is 0% and the maximum moment value is 75.02 kN.m.

THE UTILIZING OF RECYCLED PLASTIC WASTE AS AN ALTERNATIVE FOR ZERO CEMENT PAVING BLOCKS

The problem of plastic waste that needs to be handled and managed optimally can cause environmental damage. This study aims to test the compressive strength and water absorption value of paving blocks made of plastic which are designed using a mixed variation of V50-50 (50% sand, 50% plastic), V25-75 (25% sand, 75% plastic) and V0-100 (0% sand, 100% plastic) of the total proportion of the paving blocks mix. The method is carried out by melting PP (Polypropylene) mineral glass plastic, mixing with sand based on variations, printing according to the size of the paving block, and using as a test sample in the form of a dice. The average compressive strength test results show that the model with code V25-75 has a relatively higher compressive strength value than V50-50 and V0-100. The average compressive strength value of the sample with code V25-75 is 11.53 MPa, followed by code V50-50 of 9.63 MPa, and the lowest is coded V0-100 of 3.70 MPa. The compressive strength value is influenced by the optimal percentage between sand and plastic; plastic serves as a binder for sand in a mixture of paving blocks. The rate of water absorption value will continue to decrease along with the addition of plastic waste in the paving block mixture; V50-50 is 1.44, V25-75 is 0.88, and V0-100 is 0.16. This research is expected to be applied by the community to make paving block products to reduce the amount of plastic waste globally.

Assesmen Bangunan Gedung Dengan Metode Non Destructive Test (Ndt) Dan Destructive Test (Dt)

Existing building testing is carried out for various purposes that are likely to change the quality of a structure or because the building experiences or is indicated to have errors in workmanship or differences with technical specifications. Ideally, testing is carried out (non destructive) and (destructive test). The buildings used as test locations are the Faculty of Economics UNM, Tellu Cappa Postgraduate UNM, UNM Integrated Laboratory. The observation technique is to collect standards on direct implementation in the field and processing data obtained in the field. Based on the results of observations obtained the implementation method of schimdt hammer test and core drill data processing results schimidt hammer test building Faculty of Economics UNM for all elements obtained an estimated average compressive strength value of 459.4 kg / cm2, UNM Engineering Integrated Laboratory 445.3 kg / cm2, Tellu Cappa Postgraduate UNM 342.9 kg / cm2 While the average compressive strength of core drill samples Faculty of Economics UNM 32.89 MPa, Tellu Cappa Postgraduate UNM 30.06 MPa, UNM Integrated Laboratory 32.86 MPa. In conducting the test, pay attention to the condition of the structural elements or components that will be sampled.

ANALYSIS OF THE EFFECT OF FLY ASH AS FILLER ON THE COMPRESSIVE STRENGTH OF HIGH STRENGTH SELF-COMPACTING CONCRETE

High Strength Self Compacting Concrete is a concrete innovation with the advantage of having high workability and high concrete quality. In this research, fly ash was used as a filler. Tests carried out by using a fly ash with the percentage of 1%, and conducting a slump flow test with a curing time of 14 days. The same percentage of fly ash was also tested using three types of slump tests, namely the slump flow test, l box test and v funnel test with a curing time of 28 days. The specimens are cylindrical with dimensions of 100 mm and 200 mm. The research results with a curing time of 14 days qualified for Self-Compacting Concrete according to EFNARC with a slump flow test value of 700 mm and qualified for High Strength Concrete with an average compressive strength value of 62.14 MPa. The results of the study with a curing time of 28 days obtained Slump Flow Test values ​​of 719 mm, L Box test of 1 cm and V funnel of 19.99 seconds with an average compressive strength of 44.36 MPa at 28 days.

Analysis of the properties of chemically bound phosphate ceramics (CBPCs) produced from metakaolin with various acid phosphates

In this study, chemically bound phosphate ceramics (CBPCs), a type of geopolymer, were synthesized by reacting metakaolin (MK) with acidic solutions of phosphoric acid (PA), potassium dihydrogen phosphate (KDP), calcium dihydrogen phosphate (CDP), and aluminum dihydrogen phosphate (ADP). The obtained CBPCs were characterized using thermal analysis (DTA-TG), X-ray diffraction, dilatometry, and scanning electron microscopy and by their real density, porosity, water absorption, and compressive strength. The analyses revealed that the used acid phosphate type strongly influenced the properties of the resulting CBPCs. The best compressive strength results were found in CBPCs obtained using ADP, with an average value of 34.50 MPa and average porosity of 23.21%. For CBPCs obtained from PA, CDP, and KDP, the average compressive strength values were 14.18, 8.17, and 2.84 MPa, respectively; their average porosities were 18.79%, 36.23%, and 37.90%, respectively. The results demonstrate that CBPCs produced with MK can be cured at room temperature and that CBPCs obtained with ADP have higher compressive strength values than these of the other acids.

Pemanfaatan Abu Serabut Kelapa dan Serbuk Cangkang Telur Terhadap Kuat Tekan Beton

Indonesia is the largest coconut fiber producing country in the world and has not been able to process it optimally. Egg shell waste is also one of the wastes that is often encountered because many food raw materials use eggs. This research was conducted to determine the value of the compressive strength of concrete with the addition of coconut fiber ash and eggshell powder as a substitute for cement and which of the percentages of 0%, 0.5%, and 1.5% added mixture has optimal compressive strength for concrete quality. K – 225 or equivalent to 19.3 MPa at 28 days of age. The method used in this study is an experimental method according to SNI 03-2834-2000 concerning Procedures for Making Plans for Normal Concrete Mixture. The results of this study revealed that the addition of coconut fiber ash and eggshell powder to the concrete mixture decreased the compressive strength compared to normal concrete but not significantly. The average compressive strength value of normal concrete is 19.58 MPa. Whereas the compressive strength of concrete with the highest added material is the percentage of 0.5% coconut fiber ash and 0.5% eggshell powder with an average compressive strength of 19.30 MPa.

Pemanfaatan Limbah Serbuk Gergaji Kayu Jati (Tectona grandis) Sebagai Bahan Campuran dalam Pembuatan Paving Block Porous

The growth of development that continues to increase in each region results in reduced water catchment areas, to overcome this it is necessary to create artificial recharge. Artificial infiltration aims to preserve groundwater as a source of life to be maintained, for reasons of beauty many building service users prefer paving blocks as an alternative to pavement covering the ground surface, installations that have gaps on the sides of the paving can transmit water by 30-50% . Paving block is a building material composed of portland cement, aggregate, water, with or without additives but does not reduce the quality of the paving itself. Porous paving blocks are paving blocks made from added materials in the form of biomass waste, one of which is teak wood sawdust. This research was conducted to make porous paving blocks with quality standard D, which are used for parks floor and other uses. The composition of the materials used were cement and sand (1:3), added with teak sawdust in the treatment of P1 as much as 2%, P2 as much as 4%, P3 as much as 6%, and P4 as much as 8% of the total weight of the material 2.5 kg. Based on (SNI 03-0691-1996), paving block sizes have a minimum thickness of 60 mm with a tolerance of ±8%. The porous paving block produced meets SNI standards with side lengths of 100 mm and thicknesses varying between 56 – 72 mm. Paving blocks with quality standard D have a minimum compressive strength value of 8.5 MPa and a maximum water absorption capacity of 10%. The results of this research shown the paving block P1 treatment has an average compressive strength value of 16.05 MPa with an average water absorption capacity of 6.89% which are in paving block type D quality standard range. Keywords: Leachate, Paving Block Porous, Teak Wood Sawdust, Waste.

Investigation of the microstructure, hardness, and compressive properties of TaC-reinforced lamellar graphite cast irons

Tantalum Carbide (TaC) reinforcement was made to lamellar graphite (gray) cast irons that were produced in the physical conditions of a foundry at reinforcement ratios of 0%, 0.025%, 0.155%, and 0.285%. Samples complying with standards were prepared using the TaC-reinforced lamellar graphite (gray) cast iron alloys that were produced, and Brinell hardness tests, compressive strength tests, and microstructural analyses were conducted. According to the test results, the highest average Brinell hardness value was found as 231 HB in sample A which was reinforced at a ratio of 0.025%. In general, as the reinforcement ratio increased, there was an increase in the hardness test measurement results. The highest average compressive strength value was found as 949 MPa in sample C which was reinforced at a ratio of 0.285%. In general, as the reinforcement ratio increased, there was an increase in the compressive strength values. The results of the microstructural analyses showed that the reinforcement material was dispersed into the matrix.

Relative experimental evaluation of properties of concrete with addition of super – Plasticizers

The second most – widely used man – made material worldwide is considered to be as Concrete. Concrete is a simple construction material, produced with four basic ingredients: Cement, Fine Aggregates, Coarse Aggregates and Water. But, with the need of modification on the properties of concrete under different circumstances and various application areas, admixtures were also added while making the concrete mix. As per the latest codal provisions of IS 10262: 2019, admixtures had been added as a core ingredient, along with the four basic ingredients of concrete mix, for the determination of the quantity of each ingredient in making a concrete batch of desirable grade. With more technological advancements in the industry of cement and concrete, researchers, academicians and engineers are in a constant trend in trying to modify the properties of concrete by using various additives (such as chemical admixtures) in order to develop specialized concretes, which enhances the strength of the concrete along with the workability of concrete, thereby increasing the lifespan of the concrete – made structure. This study gives a general idea of how the different doses of chemical admixture alters the various properties of both fresh concrete and hardened concrete, such as workability and strength of concrete in compression, tension and flexure. The laboratory experiments were conducted for the determination of the characteristics of the concrete in both fresh and hardened state as per the procedures laid in Indian Standard Codal Provisions. Different dosages of chemical admixture used varies from 0% to 3% and comparable results were obtained with plain cement concrete, having 3 batch of M 20 grade concrete, each batch were tested with number of samples for getting an average value of workability and compressive strength, tensile strength and flexural strength. The result with 2% addition of admixture shows the optimum results.

Effect of Diluent Amount on Properties of Porous NiAl

Porous NiAl parts were formed by using Ni and Al elemental powders, preformed NiAl as diluent and NaCl particles as space holder (SH). The aim of utilizing preformed NiAl (30%-40%) as a diluent was to preserve the shape of the products. The amounts of the SH NaCl particles in NiAl were 25-50-75 vol.% and their sizes were in 300-500 µm range. Porous NiAl samples were prepared by volume combustion synthesis (VCS). The adiabatic temperatures of the Ni+Al mixtures having 30 and 40% diluent NiAl were calculated as 1638.9 and 1460.8°C, respectively. Formation of NiAl phase was verified by XRD analyses. In the green pellets, the total porosity amount was higher than the added NaCl amount. Also it was slightly higher in the product pellets than in the green pellets before VCS. Compressive strength and microhardness values of the samples which contained 30% diluent NiAl were higher than the samples which contained 40% diluent. Average compressive strength values of the products that were obtained by 25% NaCl and 30 and 40% diluent NiAl additions were 112.0±29.5 and 66.0±20.5 MPa, respectively.

Irregular Shape Effect of Brass and Copper Filler on the Properties of Metal Epoxy Composite (MEC) for Rapid Tooling Application

Due to their low shrinkage and easy moldability, metal epoxy composites (MEC) are recognized as an alternative material that can be applied as hybrid mold inserts manufactured with rapid tooling (RT) technologies. Although many studies have been conducted on MEC or reinforced composite, research on the material properties, especially on thermal conductivity and compressive strength, that contribute to the overall mold insert performance and molded part quality are still lacking. The purpose of this research is to investigate the effect of the cooling efficiency using MEC materials. Thus, this research aims to appraise a new formulation of MEC materials as mold inserts by further improving the mold insert performance. The effects of the thermal, physical, and mechanical properties of MEC mold inserts were examined using particles of brass (EB), copper (EC), and a combination of brass + copper (EBC) in irregular shapes. These particles were weighed at percentages ranging from 10% to 60% when mixed with epoxy resin to produce specimens according to related ASTM standards. A microstructure analysis was made using a scanning electron microscope (SEM) to investigate brass and copper particle distribution. When filler composition was increased from 10% to 60%, the values of density (g/cm3), hardness (Hv), and thermal conductivity (W/mK) showed a linear upward trend, with the highest value occurring at the highest filler composition percentage. The addition of filler composition increased the compressive strength, with the highest average compressive strength value occurring between 20% and 30% filler composition. Compressive strength indicated a nonlinear uptrend and decreased with increasing composition by more than 30%. The maximum value of compressive strength for EB, EC, and EBC was within the range of 90–104 MPa, with EB having the highest value (104 MPa). The ANSYS simulation software was used to conduct a transient thermal analysis in order to evaluate the cooling performance of the mold inserts. EC outperformed the EB and EBC in terms of cooling efficiency based on the results of thermal transient analysis at high compressive strength and high thermal conductivity conditions.

Utilization of flue gas desulfurization gypsum waste as a partial substitution of cement for the production of concrete bricks

This research aims to determine the use of flue gas desulfurization gypsum waste as a partial substitution of cement for the manufacture of concrete bricks. Flue gas desulfurization gypsum is waste from the tin processing that takes place. This research uses flue gas desulfurization gypsum waste compositions of 5%, 15%, 25%, and 35% by weight of cement. The design of the concrete brick was mixed with a design compressive strength value of 5 MPa and is included in the class II quality category according to SNI 03-0349-1989 concerning concrete bricks for masonry walls with a water-cement factor value of 0,4. The size of the test object is 40 x 10 x 20 cm, where the making of concrete brick uses a hydraulic press machine with a total sample of 40 pieces. The results showed that the use of flue gas desulfurization gypsum could increase the compressive strength with a substitution percentage of 5% with an optimum average compressive strength value of 8,569 MPa and the optimum water absorption value with a 5% substitution percentage of 9,315%. The percentage above 5% experienced a decrease in the average compressive strength and an increase in the average water absorption capacity of the concrete bricks.

Pengaruh Penggunaan Limbah Abu Sekam Padi dan Viscocrete 1003 Terhadap Kuat Tekan dan Kuat Lentur Beton

The purpose of this study was to determine the effect of the use of waste rice husk ash and viscocrete 1003 on the compressive strength and flexural strength of concrete with variations in the mixture of rice husk ash waste 0%, 25%, 30% and viscocrete 1003 0.6%. The results showed that the chemical content of rice husk ash that had been burned was high SiO2 (Silicon Dioxide), which was 75.5 ─ 87.9 % by weight, while the chemical content of unburned rice husk ash was SiO2 (Silicon Dioxide). Which is high that is equal to 86.9 ─ 94.7% by weight. The compressive strength test value of each variation of the specimen which is converted into 28 days of age is for variation 0% the average compressive strength value is 21.590 MPa, for variation 25% with an average compressive strength value of 15.635 MPa and 30% variation with the average compressive strength value is 11.486 MPa. So it can be concluded that the average compressive strength value from the 0% variation to the 25% variation has decreased by 0.05955%, while from the 25% variation to the 30% variation it has decreased by 0.0415%. The flexural strength test value in terms of the maximum average moment on the slab for each variation of the test object converted into 28 days of age is for 0% variation of 146.820 kN.m, for 25% variation of 165.760 Kn.m and variation of 30% of 170.490 Kn.m. So it can be concluded that the average flexural strength value from the 0% variation to the 25% variation has increased by 3.13%, while from the 25% variation to the 30% variation it has increased by 3.36%.

Pengaruh Penggunaan Serbuk Arang Batok Kelapa Terhadap Kuat Tekan Beton

Processing of coconut shells into charcoal powder as a concrete mixture. The use of coconut shell charcoal powder on the compressive strength of concrete aims to be a substitute for cement for normal concrete compressive strength and to determine the optimum concrete compressive strength after substitution of cement using coconut shell charcoal powder. In this study the use of coconut shell charcoal powder as a cement substitution with variations of 0%, 2.5%, 5% and 7.5%. Concrete testing was carried out at the age of 28 days after treatment by being immersed in water. The results of the analysis showed that the average compressive strength value of the addition of coconut shell charcoal powder at variations of 5% and 7.5% decreased by 11% and 12.57% because with the increasing number of calcium hydroxide formed, the cement adhesion will decrease so that the structure inside will be weak and cause the compressive strength to be low, while the variation of adding coconut shell charcoal powder 2.5% has an increase of 2.07% against normal concrete compressive strength. From the results of the characteristic concrete compressive strength obtained with substitution variations of 2.5%, 5%, and 7.5% respectively of 278.74 kg/cm2, 243.43 kg/cm2 and 238.96 kg/cm2, the concrete These include class II K 275 concrete (middle class concrete) structural concrete.