Design Compressive Strength Research Articles

Material Characteristics of Compressed Dry Masonry Made of Medium-Size Elements with Perlite Aggregate

Dry masonry is a type of construction that is nowadays used to a limited extent in the construction sector, including the housing sector. A lack of codified computational methods enabling engineers to design consciously is one of the factors limiting the development of dry walls. This article presents results from testing an innovative solution for dry masonry made of medium-size elements with expanded perlite aggregate. Material with this type of aggregate has a low bulk density (390 ± 10% kg/m3), which allows the production of large blocks and significantly reduces the value of the thermal conductivity coefficient λ = 0.084 ± 0.003 W/m·K. The results obtained were used to determine material parameters for designing a structure mainly exposed to vertical load. The important practical significance of the presented research results from the lack of provisions, specifications or standards allowing for the design, calculation and construction of dry masonry; it is not possible to analyse the behaviour of this type of structure and to design it consciously and safely. The presented research is therefore an important source of information on mechanical parameters essential for the design of structures and provides tools for this. As a result of the tests of nine panels, the mean compressive strength was determined (1.085 N/mm2), and then the procedure of “design assisted by testing” implemented into Eurocode was used to determine characteristic (0.873 N/mm2) and design compressive strength (0.565 N/mm2). Using the relationships σ-ε, an attempt was made to identify material models for the linear and non-linear analysis of the structure and for designing cross-sections. The material models were made considering increased non-linear deformations of a structure under low stresses (the compression toe) which are true and typical for dry masonry. A specific deformability of dry masonry, slightly different to that in masonry structures joined together with mortar, also affects the reduction factor for load-bearing capacity due to second-order effects. Reduction factors determined from true non-linear deformations were lower than the values specified by EC6 for masonry structures.

Physical and numerical tests on adjustable–height structures of high–speed railway transition section

The disparity in stiffness and differential settlement between the subgrade and rigid structures can lead to track irregularities within transition sections, resulting in significant train vibrations and impacts. This study proposes an adjustable–height subgrade structure for transition sections by introducing a raft slab to divide the subgrade into upper and lower parts. When settlement occurs in the subgrade, the raft slab can be elevated using height–adjustment techniques to compensate for the settlement. To this end, large–scale physical model tests are conducted under train loading to verify the design's rationality and to elucidate the influence of settlement magnitude and train speed on the stress and deformation of the slab. The experimental results indicate that the maximum principal stress and maximum shear stress of the slab generally increase with settlement magnitude and train speed, and the area near the abutment end is the most unfavorable position for the deformation of the slab. However, it is still lower than the design compressive strength of the C40 concrete structure. Thus, the designed adjustable–height structure meets the load–bearing requirements under train loading. Additionally, a numerical simulation model of the adjustable–height structure is developed to investigate the recovery capabilities and stress distribution of the settled raft slab. The results indicated that whether the lifting operation employed linear load or equal load methods, the raft slab primarily endured compressive stress, and there is stress concentration at the lifting points. For the same lifting displacement, the linear load method proved to be more reasonable than the equal load method. These findings have significant practical and theoretical implications for ensuring the safe and smooth operation of high–speed railways, effectively addressing the post–construction settlement deformation control challenges in ballastless track transition sections.

The Influence Of Adding Superplasticizer With Time Interval And Variation Of Water Reduction On The Early Strength And Workability Of Concrete

Acceleration of early strength of concrete can be obtained by reducing water in the concrete mixture followed by addition of superplasticizer. The application of the addition of superplasticiser to water-reduced concrete mixtures requires innovation in providing a time lag to produce good workability. This study analyzes the effect of giving a time delay when adding superplasticizer followed by reducing water with certain variations on the workability and early strength of concrete. The results of this research are very important for the concrete industry with the purpose of shortening the removal time of formwork and optimizing the construction process. Water cement ratio is adjusted by reducing its volume by a fraction of 10% to 30%, superplasticizer 1% to the weight of cement is added in two stages, during the initial mixing and after one or two hours afterwards. 0.3% retarder was added to control homogeneity during mixing. The test results concluded that the reduction of water that provided the highest increase in concrete compressive strength at 4 days was LN25-1 of 21.94 MPa (87% of the design compressive strength) and LN20-2 of 19.12 MPa (76% of the compressive strength plan). The optimal amount of water reduction at the initial age of the concrete is 20 – 25% of the design water weight. Giving a time lag does not reduce the increase in concrete strength due to the addition of superplasticizer.

Optimization of silty soil solidification agent ratio and mechanism of strength change based on design-expert

ABSTRACT In order to achieve the resource utilization of silty soil, based on the solidification mechanism of existing inorganic solidification agents, coal gangue and fly ash were selected as substrates, and quicklime and sodium silicate were used as activators to study a new type of muddy soil solidification agent. This project adopts mixture experimental design and unconfined compressive strength testing methods, and uses design expert software to analyze each component to obtain independent variable relationship strength prediction formulas. By using scanning electron microscope, Particles (Pores) and Cracks Analysis System, the changes in micro pore structure characteristics of Reinforced soil were obtained. The research results indicate that the relationship between the influence of various variable factors on strength gain is as follows: sodium silicate>calcium oxide>fly ash>coal gangue. As the age increases, the porosity shows a trend of first increasing and then decreasing. It has been revealed that the strength growth of Reinforced soil with curing agents is mainly due to the compaction and filling effects of hydrated calcium silicate, hydrated calcium aluminate, and a small amount of ettringite. This study is expected to provide reference for the solidification of high moisture content muddy soil.

SO SÁNH CƯỜNG ĐỘ CHỊU NÉN CỦA BÊ TÔNG SỬ DỤNG CỐT LIỆU TÁI CHẾ VỚI BÊ TÔNG THÔNG THƯỜNG, TRƯỜNG HỢP CÓ SỬ DỤNG TRO BAY VÀ KHÔNG SỬ DỤNG TRO BAY

This article presents the results of research evaluating the compressive strength of concrete using recycled coarse aggregate, in the case of using fly ash (CP1) and without using fly ash at a content of 5% (CP2). The experimental samples were compressed to test the compressive strength value at different times, including 7 days old, 14 days old and 28 days old. The study designed a recycled concrete composition with a 50-50 ratio of regular aggregate and recycled coarse aggregate, and the concrete has a design compressive strength of 15 Mpa. The compressive strength of concrete was studied and compared in cases with and without fly ash, and compared with another research result on concrete using recycled coarse aggregate.

Penggunaan Abu Sekam Kopi dan Ordinary Portland Cement terhadap Kuat Tekan Beton Normal

Cement is one of the binders which is commonly used as a concrete-forming material. Currently, there is a lot of coffee husk waste in Takengon, Central Aceh Regency, which contains silica. The basis of using coffee husk ash and OPC cement as an adhesive on the normal compressive strength of concrete. This study aims to determine the influence of using coffee husk ash and OPC cement as an adhesive on the compressive strength of normal concrete at a percentage of 5%, 10% and 15%. The research specimen is cylindrical shape with 15 cm diameter and 30 cm height. The test was carried out at the age of 7 and 28 days by using a compressive strength testing machine. The method of making the specimen is in accordance with the SNI 7656-2012 standard. It is found from the results in the laboratory, coffee husk ash obtains silicate compounds (SiO2) 29.11%, magnesium oxide (MgO) 4.92%, calcium oxide (Cao) 5.33%, ferrioxide (Fe2O3) 4.25% and aluminum oxide (Al2O3). The average compressive strength test results of 7-day old concrete at the percentage of 5% coffee husk ash mixture was 20.21 MPa, at 10% was 20.03 MPa and at 15% was 17,25 MPa. The average compressive strength of concrete at 28 days of age with 5% coffee husk ash mixture is 20.27 MPa at 10% coffee husk ash mixture percentage 19.70 MPa and 15% coffee husk ash mixture 15.46 MPa. Comparison of the results of the compressive strength test for concrete at 7 and 28 days was higher for concrete at 7 days. The results of the different compressive strength tests between the ages of the concrete are caused by the high percentage of coffee husk ash mixture where the higher the coffee husk ash percentage, the weaker the adhesion to the concrete. The percentages of coffee husk ash and OPC cement that meet the design compressive strength of 20 MPa are at 5% and 10% respectively.

Kekuatan Tekan Beton Berpori Additive Sika Fume Mix Self Compacting Concrete

This research aims to determine the effect of adding the additive Sika Fume on the compressive strength of hollow 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 hollow concrete with the addition of sika fume with a variation of 0% and 2% of the weight of cement, the experimental results obtained for the compressive strength of hollow concrete for 28 days of concrete with a variation of 0% with an average of 16.83 Mpa. For a variation of 2% with an average of 17.42 Mpa. So it can be concluded that concrete with a variation of 2% with an average of 17.42 Mpa is the variation with the highest compressive strength value and reaches the design compressive strength. Meanwhile, the 0% variation with an average of 16.83 Mpa is the lowest compressive strength value and does not reach the design compressive strength.

Influence of coatings on residual strength of geopolymer concrete columns subjected to fire exposure: An experimental investigation

Fires occurring within buildings present a grave concern, as they entail substantial risks to human lives, property, and the environment. Implementing appropriate fire safety measures becomes imperative to mitigate the occurrence of fires and ensure efficient response in the event of an incident. The primary aim of the study is to examine the performance of various coatings on the residual strengths of the reinforced normal strength self-compacting geopolymer concrete (NSGC) and high strength self-compacting geopolymer concrete (HSGC) columns subjected to standard temperature exposure in accordance with ISO 834 guidelines. The design compressive strength of the concretes was 36.12, 57.06 and 52.8 MPa. Two types of coating were employed in the present investigation namely ceramic wool wrapping and high alumina cement. A computerized electric furnace is used to heat the column specimens. Amongst the forty-two columns developed, six specimens tested without temperature exposure and protective coating as a reference specimen. Twelve specimens were heated as per ISO fire curve and tested to assess the residual axial strength performance and twenty-four specimens were coated with protective layers, then heated and tested to assess the post fire performance. It is exemplified that the composite protective coating offers effective resistance to concrete, gaining optimum axial strength performance. The findings show that these fire protecting composites have a high potential for utilizing as new strengthening techniques for reinforced concrete (RC) columns.

Analisis Penambahan Serat Strapping Band Rigid Pavement Terhadap Kuat Lentur Beton

The development of science, especially in the field of transportation, especially roads, requires adequate infrastructure in the form of roads or pavement that is suitable for the conditions in the field. This research aims to determine the analysis of the addition of strapping band fibers on the flexural strength of concrete, the variation in influence is 0.5%, 1 .0%, 1.5%, the best composition for making rigid pavement flexural strength. This research uses experimental research methods, namely research in the laboratory which aims to investigate the effects of each other and compare the results. The research results of 4 variations, namely 0% (normal), 0.5%, 1.0% and 1.5% of fine aggregate, in testing concrete aged 28 days on normal concrete were 3.333 Mpa, for variations of 0.5% on average an average of 2,800 Mpa, a 1.0% variation an average of 2,133 MPa, and a 1.5% variation an average of 1,333 MPa. So it can be concluded that concrete with a variation of 0.5% achieves the design strength and is suitable for use. Meanwhile, variations of 1.0%, 1.5% do not reach the design compressive strength and are not suitable for use in construction.

Impact strength and weight loss of fiber-reinforced concrete exposed to elevated temperatures

The article presents experimental results that were directed to explore the effect of weight loss on the residual repeated impact strength of concrete exposed to high temperatures. The experimental program included the testing of shallow cylindrical specimens under repeated impact loading following the ACI 544-2R test setup recommendations. Five concrete mixtures were prepared for this purpose to evaluate the influence of two major parameters, which are the concrete design compressive strength and the volumetric content of fiber. Three plain mixtures with three levels of design strength including normal-strength and high-strength concrete were prepared in addition to two fibrous mixtures that have the same constituents of the normal-strength mixture. Hooked-end steel fibers were used in the fibrous mixtures at two volumetric contents of 0.5 and 1.0 %. In addition to the repeated impact strength, the compressive strength was also tested using 100 mm cubes. A group of six shallow cylinders and three cubes was tested at room temperature without heating as a reference group from each mixture, while three similar groups were subjected to 200, 400 and 600 °C then tested after natural cooling. The weight loss was recorded for all heated specimens. The results showed that both the specimen weigh and the repeated impact exhibited a trend of continuous decrease with the increase of temperature. However, the repeated impact suffered serious damages after exposure to 200 °C and almost faded after exposure to the higher temperatures, while reasonable decreasing weight losses were recorded at all temperatures.

A New Insight into the Design Compressive Strength of Ultra-High Performance Concrete

Compressive strength is one of the most critical mechanical properties of various types of concrete and is the main input variable for structural concrete design. Recently, with the advances in concrete technology, applications of fiber-reinforced concrete (FRC), including ultra-high performance concrete (UHPC), have grown rapidly. These new types of concrete are well known to exhibit superior mechanical characteristics such as compressive strength, fracture toughness, and durability compared to conventional concrete and thus are popularly used in urgent repair jobs where compressive strength is an important parameter to determine the required curing time until open to the public. Considering the importance of compressive strength in practice, this study aims to evaluate the effect of age and maturity on the compressive strength characteristics of three different types of concrete, namely UHPC with micro and macro steel fibers, FRC, and plain concrete, and to propose a new design strength criterion for UHPC. To this end, 180 concrete cube specimens were tested at 12 different ages between 3 and 126 days. The results indicated that irrespective of the type and presence of fibers, UHPC gained more than 90% of their ultimate compressive strength after only 21 days, while FRC and plain concrete specimens required a longer time (i.e., 28 days) to achieve 90% of their ultimate strength. Therefore, UHPC may adopt a 21-day compressive strength as a design input instead of a 28-day compressive strength commonly required for structural concrete specified by many codes of practice. Moreover, the obtained experimental results were compared with existing compressive strength predictive models in the codes of practice.

Analisa Nilai Kuat Tekan dan Kuat Lentur Terhadap Tambah Polypropylene Fiber Curved Form Pada Campuran Beton Normal

The increase in the need for building material of concrete for infrastructure need to be improved through technology inovation. Various methods have been developed to increase the compressive strength and flexural strength of concrete, one of them by adding micro reinforcement such as fiber. In this research, polypropylene fiber curved form is used. This research aims to analyze the influence of adding fiber into the design concrete mix on their compressive and fexible strength. In this study, the mix design used the SNI 7656-2012 method and the design compressive strength is 30 Mpa, the design slump height is 70 mm – 100 mm. Normal concrete is added with polypropylene with the composition of 3 kg/m3, 4 kg/m3, 5 kg/m3. 24 cylinder (15 x 30 mm) test objects are provided, and 24 beam (15 x 15 x 60 cm) test objects are provided, with 3 tests for each variety for the age of 7 and 28 days. Based on the test the compression strength results of normal concrete for the age of 28 days are obtained as 35.19 Mpa. Optimum value is obtained in the variety of 4 kg/m3, in the age of 7 days as 31,88 MPa or 15,74% increase, in the age of 28 days as 40.94 MPa or 16.33% increase from the normal concrete compressiven strength. The flexural strength of normal concrete aged 28 days is found to be 4.76 Mpa. The optimum value of flexible strength with the variety of 4 kg/m3, in the age of 7 days is obtained as 4,76 Mpa or 5,76% increase, in the age of 28 days is obtained as 5.87 Mpa or increase of 23.26% from the flexible force of normal concrete. Based on the results of this research, the adding of polypropylene fiber into the concrete mix can increase its mechanical properties, mainly the compression and flexible strength.

A Study to Improve the Reliability of High-Strength Concrete Strength Evaluation Using an Ultrasonic Velocity Method.

The ultrasonic pulse velocity (UPV) technique, which is an efficient technique for concrete quality evaluation, can be affected by several factors. Many studies have proposed compressive-strength prediction models based on UPV in concrete; however, few studies have investigated the factors resulting in statistically different UPV results for different models. This study examined the difference between compressive strengths of various concrete specimens calculated by age-dependent and temperature-dependent UPV-based prediction models. Furthermore, a statistical analysis was conducted to evaluate the influence of aggregates and water/cement ratio (design compressive strength), which are said to affect UPV, on the compressive-strength prediction models. The experimental results revealed that the residual compressive strength of concrete after high-temperature exposure was about 9.5 to 24.8% higher than the age-dependent compressive strength. By contrast, after high-temperature exposure, UPV tended to be about 34.5% lower. The compressive strengths and UPVs were significantly different with respect to high temperature, aggregate density, and design compressive strength. The compressive-strength prediction model derived from the regression analysis showed a high R2 (average 0.91) and mean error converged to zero compared to the compressive-strength prediction model without considering these factors. Finally, the differences between the age- and temperature-based compressive-strength prediction models were analyzed according to the corresponding microstructures.

Limestone-Calcined Clay (LC2) as a supplementary cementitious material for concrete

In this work, limestone-calcined clay (LC2) is studied as an alternative supplementary cementitious material (SCM), combining two widely available resources – calcinated kaolinitic clay and limestone, to partially substitute portland clinker. The primary goal is to assess the potential of LC2 to produce moderate to high strength concretes with design compressive strengths of 20 to 50 MPa. For this purpose, 27 mixes with LC2 were prepared with a range of binder contents and water-binder ratios, and the performance was benchmarked against those of mixes having fly ash (PFA). In addition to the quantification of strength and concrete resistivity, life cycle assessment was performed for the concretes considering a typical situation in India. The efficiency of concretes made with LC2, PFA and ordinary portland cement (OPC) was analyzed using the energy intensity index (eics) and apathy index (A-index) as sustainability indicators. This framework establishes the sustainability potential of the LC2 with insights on the influence of strength on the indicators. It is concluded that the LC2 concretes with 45% replacement level, w/b≤0.45 and binder content lower than 400 kg/m3 possess the highest sustainability potential, among the concretes studied here.

Experimental study on nonlinear ultrasonic characterization of concrete during crack propagation

Damage and failure of concrete structures are essentially caused by crack initialization and expansion. Conventional ultrasonic tests cannot detect changes in the micro-cracks in concrete. Second harmonic generation (SHG) is effective at characterizing the micro-damage. However, research on the influence of micro-cracks on the nonlinear parameter β is still insufficient. Three cubic concrete specimens 150 mm × 150 mm× 150 mm were fabricated, and the design and average compressive strength were 30 MPa and 39.24 MPa, respectively. Before compressive loading, the integrity of concrete specimens was verified using scanning electron microscopy. The load rate is set to 0.6 kN/s during the test. A simultaneous test system for stress σ, strain ε, and nonlinear parameter β was designed, and the regularity of the nonlinear parameter β during compressive loading was investigated. The nonlinear parameter β increases significantly at the beginning of the compressive load. As the load continues to increase, the nonlinear parameter β decreases rapidly and then fluctuates during the subsequent loading. Furthermore, attenuation was also analyzed in this experiment based on the head-wave amplitudes. At the beginning of the compressive loading, the attenuation is weak as no obvious damage exist in concrete. The non-linear parameter β is less affected by the attenuation when the integrity of the concrete specimens is good. When the cracks expand and penetrate, strong attenuation can be observed at the fundamental and second harmonic waves. The results of the experiment have considerable importance with respect to the method of SHG for micro- and macro-scale damage in concrete.

Underwater surface abrasion of conventional and geopolymer concrete using the ASTM C1138 approach

This study focuses on the development of unique geopolymer-based composites made using industrial byproducts and waste materials. The first test variable was the compressive strength grade, where conventional concrete specimens with ordinary Portland cement (OPC) and GPC specimens having three target design strengths (20, 30 and 40 MPa) were prepared and tested. All specimens were tested at different ages, which is the second variable of the study, where early ages (3 and 7 days) and mature age (28 days) were adopted. It is worth mentioning that both geopolymer and concrete samples had the exact quantities of filler and binder materials. Then, the specimens were tested following the procedure of standard ASTM C1138 approach under-water abrasion tests, which were conducted at 6 intervals of 12 h each. The recorded abrasion results revealed higher abrasion losses for specimens with lower design strengths regardless of the type of concrete. Besides, the influence of the sample's age on enhancing the abrasion resistance was more apparent in conventional concrete samples than geopolymer ones since the last gained their design strength early, about three days. The GPC specimens exhibited lower abrasion losses compared to their corresponding OPC ones revealing a better abrasion resistance. The difference was the highest at the age of 3 days due to the early strength development of GPC. The abrasion resistance enhancement of GPC specimens compared to their corresponding OPC ones at 3 days was 72% for the design strength of 20 MPa and around 55% for the higher design compressive strengths.

Eco-friendly concrete with waste ceramic tile as coarse aggregate: mechanical strength, durability, and microstructural properties

The drive towards circular economy in achieving sustainable concrete cannot be overemphasized. The recycling of waste tiles from the ceramic industry, demolished buildings, or during the construction process could be one way of solving the waste generated from ceramic tiles. This study investigates the use of waste ceramic tiles as coarse aggregates in concrete at replacement levels of 0, 10, 20, 30, 50, and 100% by weight of natural coarse aggregate. Concrete cylinders were cast and tested for compressive and splitting tensile strength after a curing period of 7, 14, and 28 days. Further, the durability of the concrete was investigated via water absorption and total permeable pore volumes in all the concrete mixes. The results indicate that the strength of concrete decreases as the percentage of waste ceramic tile aggregate increases. However, adding 10% tile aggregate in concrete seems acceptable as the strength reduction was relatively low. The water absorption and voids increase as waste ceramic tile aggregate increases. Analysis of variance (ANOVA) test was performed to investigate the statistical significance of the waste ceramic tile aggregate on the properties tested. Artificial neural network (ANN) was also performed to predict the compressive strength of ceramic tile concrete. Based on the outcomes, it is recommended to use 10–20% of waste tile aggregate in concrete production where design compressive strength is less than 20 MPa, which can also reduce the demand for new aggregate, reduce the cost of the project, save the dumping issue, and protect the environment.

Utilization of plastic bottles and fiber mask in eco-friendly concrete mixtures

Eco-friendly concrete uses less waste material which has less negative impact on the environment. This research utilizes PET plastic bottles and masks as a substitute for aggregate in concrete. The aim is to find out whether the compressive strength of eco-friendly concrete meets the requirements of structural concrete. The method used is planning mix design on seven samples, one sample of normal concrete and six samples of concrete with replacement of aggregate composition. Samples with aggregate replacement were designed from variations of 0.1%, 0.2% and 0.3% by weight of cement and PET plastic bottles with composition variations of 5% and 10% of coarse aggregate. The test results of the average compressive strength of concrete for 28 days are 235 KN/m2 for normal concrete; 117 KN/m2, 85 KN/m2; 149 KN/m2; 64 KN/m2, 42 KN/m2 and 21 KN/m2. The highest average compressive strength was obtained at 149 KN/m2 but did not reach the design compressive strength of 235 KN/m2. It can be concluded that the use of substitute aggregates from PET plastic bottles and masks did not get concrete results that match the compressive strength of the plan, but the concrete still meets the requirements for the compressive strength of low-strength structural concrete.

Understanding the environmental, economic, and social impact of fly ash utilization on early-age high-strength mass concrete using life cycle analysis

High-strength mass concrete mixtures are a crucial component of numerous structures nowadays. However, concrete greatly impacts the environment, economy, and society. The impact of employing fly ash in early-age, high-strength mass concrete mixtures has not yet been quantified and documented in the literature. This study aims to evaluate the impact of early-age, high-strength mass concrete mixtures and provide insight into how the current practice might be enhanced to promote sustainability. The research examines concrete mix utilized in two bridges in the Philippines with the following design compressive strengths: 55 MPa at 7 days (7OPC), 55 MPa at 28 days (28OPC), and 55 MPa at 7 days with 20% fly ash as cement substitute (7FA20). Using SimaPro 9.3, a cradle-to-gate life cycle analysis was conducted to quantify their effects based on 18 midpoint and 3 endpoint categories. Results show higher impact of 7OPC on 17 midpoint and 3 endpoint indicators was observed than on 28OPC. The most significant midpoint impacts based on normalization are fossil resource scarcity, global warming potential, ozone formation, human carcinogenicity toxicity, and terrestrial ecotoxicity. The global warming potential of 7OPC was quantified to be 636 kg CO2 eq compared to 549 kg CO2 eq of 28OPC concrete. Utilizing fly ash decreased the damage to resources (11%), human health (16%), and the environment (16%). Analysis of concrete constituents indicated that using chemical admixtures to obtain early high strength contributed significantly to fossil resource scarcity and resource damage . The framework presented in this study may be used for assessing the sustainability of utilizing other waste materials in concrete production.

Analysis of Sika Cim Additive Material Proportion In Beam-Column Joint for Fabricated House

The design compressive strength (f’c) is 21,7 Mpa / K250 and the chemical liquid was used is Sika Cim. Variation of Sika Cim adding that used is 0%; 0,3%; 0,5%; 0,8%; 1%; and 1,2% toward the weight of cement used. The each variation consists of 3 sample with 2 sample that will be at compressive strength tested at the age of 7 days, and 2 sample for compressive strength control that tested at the age of 28 days. From these all variations of Sika Cim adding, the optimum point for connection material can be founded and then it will used to fabricated house panel assembling which analise damage model of the connection. Then calculating the cost that used to make connection with the optimum Sika Cim adding, and then compare it with the cost of normal concrete with same quality. From this study can be founded that level of optimum Sika Cim is 2263,54 ml or 0,52% from the cement which used for 1 m3 volume of the concrete.. Level of Sika can increase 11,8 MPa of compressive strength or 58,38% from the normal concrete without Sika Cim. Sika Cim using at K200 concrete to produce K250 concrete is 1182,219 ml/m3, with 7,48% cost from total cost for each K200 readymix concrete. This Sika Cim adding can economize the cost for about Rp. 51.397,67 for each m3 concrete. The composition of the mixture with the optimum Sika Cim applied to the precast column beam connection material, produces a joint that has a good crack pattern.