Papers by Keyword: Compressive Strength Test

Abstract: Researchers in the field of concrete technology with the application of different admixtures are always in search of suitable admixtures to improve the workability as well as the strength of any concrete grade. An attempt was made in the present research to use chemical admixtures (superplasticizers) like sulphonated naphthalene based Apple Chemie AC-MENT-ALPHA-X5, polycarboxylic ether based Fosroc Auramix 350, sulphonated naphthalene based Fosroc Conplast SP 430, modified polycarboxylate based Du-bond DUPLAST PC P 2 and modified lignosulphate based Sika PLASTIMENT BV 40 for concrete grades M30 and M40. A literature survey revealed that all identified chemical admixtures are used for 20–25% reduced water content. A study was done to compare M30 and M40 grade concrete in both fresh and hardened states, taking water reduction into account. Experimental results showed that all admixtures demonstrate good paste-up consistency of up to 1%. As the percentage of admixtures increases, there is an increase in surface pores due to more significant air entrainment. Compressive strength results of 1% admixture content for Apple Chemie, Fosroc, and Du-bond were observed to be close to their characteristic compressive strengths for both grades, but Sika and Fosroc Auramix 350 have good compressive strength with less than 1%. As the grade of concrete improves, Conplast's effect reduces, but the Du-bond and Fosroc Auramix 350 perform excellently for split tensile strength. As the grade rises, all admixtures show increasing flexural strength levels. However, Auramix 350, with a 1.5% content for M30 grade, consistently outperforms Sika, which has a 1% content. It helped to employ up to 1% of all admixtures, but Sika reveals a cost increase of 2.5 to 7.3% for 1% and 1.5% admixture additions. The study found that Fosroc Auramix 350 could be used for both grades and still have good workability and strength.

Abstract: This paper presents an experimental evaluation of how variations in proposed parameters interfere with compressive strength resistance of mortar and concrete specimens. The results were obtained through laboratory tests in which samples were tested under varying conditions. These conditions were as follows: speed of load application (0.25, 0.50, 0.75, and 1.00 MPa/s), environmental conditions (saturated, 2 h dried, and 24 h dried specimens), curing (dry and wet), and specimen ends preparation (sulphur, neoprene, rectification, and without regularization). Comparisons were made on the basis of the compression strength resistance results and the coefficient of variation in order to analyse the homogeneity and dispersion among variables. It was found that in the case of capping, the best results were obtained by the rectification of concrete specimens. In the case of loading speed, the best results were obtained at a speed of 1 MPa/s. Dry curing showed the best results, even though not resulting in the highest resistance. The results for specimen conditions were in accordance with the expectations, with lower dispersion for saturated specimens.

Abstract: Currently in concrete technology a lot of materials were introduced to improve the quality and properties of concrete. Additional materials include the use of steel fibers into the concrete mix. With the used of steel fibers, it can enhance the strength of the concrete. In this research, two parameters will be investigated which is the volume friction of the steel fiber and the length of the steel fiber. End-hooked steel fiber with the length of 33 mm and 50 mm and the percentage of steel fiber 0.5 %, 1.0 % and 1.5 % used in this research. The size of the mold used is 100 mm x 100 mm x 100 mm. The characteristics during the fresh concrete were also investigated by conducting the slump test, compaction test and vebe test. All the samples has been cured in the water for 7^th, 14^th and 28^th days for the compressive strength test. Based on result, it was concluded that the optimum percentage of steel fiber in this report was 1.0 % for the end-hooked steel fiber with 33 mm length which provided the highest compressive strength at 28 days.

Abstract: In this paper,the mechanical properties were studied,the self compacting concrete cubic compression strength,prismatic compressive strength test,discussed two kinds of relationship between intensity index.

Abstract: Basalt fiber was added to the traditional cement-based materials to improve the physical and mechanical properties. The mixture ratio of the matrix, the basalt fiber content, and the super-plasticizer type as well as its contents were designed optimally. The fluidity test, axial compressive strength and cube compressive strength test, flexure strength test were carried out. The results show that the fluidity and the compressive strength of basalt fiber reinforced cementitious composite(BFRCC for short) reduces when the basalt fiber content increases, but the toughness of traditional cement-based materials is improved by adding basalt fiber.

Abstract: The research topic is the analysis of adobe-clay as a structural material. The behaviour of adobe brick elements of different mixtures were examined. The bricks of various ratios of clay, straw, reed and sawdust were involved in the experiment, in which the process of drying and shrinkage was investigated. Even though only a few data have been obtained so far, some important conclusions were drawn. The first drying period was approximately three weeks long in the laboratory. The tests have shown that organic components like straw, reed and sawdust slow down the drying process. In case of each mixture, a change of weight was observed sooner than shrinkage. The aim of the research is to promote the application of this building material.