MatSciRN: Concrete (Topic)最新文献

{"title":"Increasing the Crack Resistance of High-Strength Self-compacting Concrete","authors":"Vyacheslav Troуan, Bogdan Kindras","doi":"10.15587/2706-5448.2021.225500","DOIUrl":"https://doi.org/10.15587/2706-5448.2021.225500","url":null,"abstract":"The object of research is high-strength self-compacting concrete, which does not require additional vibration during laying. One of the most problematic issues of high-strength self-compacting concretes is increased cracking, associated with large shrinkage deformations of such concretes and their fragile destruction. \u0000A decrease in shrinkage deformations of concrete was established when part of the cement was replaced to mineral additives. This effect is explained by a decrease of the cement content and, accordingly, a decrease of the chemical component of the autogenous shrinkage of concrete, and an increase of the adsorptive binding of capillary moisture by mineral additives, with reduces the physical drying shrinkage of concrete. In this case, the type and dispersion of the used mineral additive can affect to the shrinkage deformations of concrete. A significant decrease in shrinkage deformations when using metakaolin is explained by an increase the amount of ettringite as a result of the reaction of active metakaolin Al2O3 with two-water gypsum of cement. It was found that the replacement of cement to 10 % of mineral additives leads to a decrease in the value of the critical stress intensity factor (SIF), which is compensated by a decrease of the fragility of concrete fracture (an increase of the area of microplastic deformations). At the same time, the type of mineral additive used does not affect to the value of the critical stress intensity factor, but significantly affects to the fragility of fracture of concrete samples. The introduction of 10 % mineral additives (to replace cement) had a positive effect on the retention of flow of self-compacting concrete mixes; the best results according to this criterion were observed when using silica fume, fly ash and limestone. All mineral modifiers, except for silica fume, led to a decrease of the compressive strength of high-strength concretes on all terms of hardening. In the case of the tensile strength of concrete at bending and splitting, with the introduction of silica fume, metakaolin and fly ash, a positive effect was observed compared to the base composition without additives. \u0000Comprehensive accounting of the results obtained will allow a reasonable approach to the design of high-strength self-compacting concretes with increased crack resistance.","PeriodicalId":193668,"journal":{"name":"MatSciRN: Concrete (Topic)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115998051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Experimental Study on the Determining the Bingham Parameters for Fresh Self-Compacting Concrete Mix Using Concrete Shear Box Method","authors":"A. N, G. S","doi":"10.2139/ssrn.3774117","DOIUrl":"https://doi.org/10.2139/ssrn.3774117","url":null,"abstract":"In the present study, the determining the Bingham parameters of self-compacting concrete (SCC) by using the shear box method under static condition. The SCC mixes were developed by absolute volume fraction method. The developed SCC mixes were tested for both empirical methods as per EFNARC guidelines and rheological method by using concrete shear box. The results show that the concrete shear box test can be used as an instrument for finding the Bingham parameters of fresh SCC mixes under static condition.","PeriodicalId":193668,"journal":{"name":"MatSciRN: Concrete (Topic)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127824534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Durability of High Strength Light Weight Aggregate (Sintagg) Structural Concrete Against Temperature Variations and Acid","authors":"P. Salgar, Pandurang S. Patil","doi":"10.2139/ssrn.3521514","DOIUrl":"https://doi.org/10.2139/ssrn.3521514","url":null,"abstract":"Extensive researches on light-weight concrete have been carried out in construction field. Use of light-weight concrete in building construction is inferior because of construction practice, understanding of design codes which are not much familiar with light-weight aggregates concrete. Recently, structural lightweight aggregate concrete is an important and versatile material in modern construction. The aim of this research work is to study the behaviour of innovative high strength structural concrete prepared by using light-weight aggregate (i.e. Sintagg). The M40 grade concrete was designed according to IS 10262:2009 method and trial cubes were casted and tested. Total 30 nos. of concrete cubes of size 15cm x 15cm x 15cm were made up with light-weight structural concrete by using light-weight aggregate. Also the mean standard deviation for this newly developed concrete was computed. The comparative study was made with normal concrete on different parameters like weight reduction, load carrying capacity and durability against chemical and temperature (fire) attack. Sintagg aggregate light weight concrete was found good in fire resistance compare to normal aggregate concrete.","PeriodicalId":193668,"journal":{"name":"MatSciRN: Concrete (Topic)","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126037691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Experimental Analysis and Comparison of Properties of Concrete with Recycled Aggregates and Partial Replacement of Cement with Alccofine","authors":"Sheetal Avinash Bhosale, Madhulika Sinha","doi":"10.2139/ssrn.3379452","DOIUrl":"https://doi.org/10.2139/ssrn.3379452","url":null,"abstract":"Increase in construction activities necessitates the utilization of raw materials in Concrete, particularly coarse aggregates which creates a threat to the untimely depletion of natural resources. Possible replacement materials would assist to slow down the risk of early exhaustion of natural resources. Recycled coarse aggregates (RCA) can supplement the natural coarse aggregates (NCA) which plays a crucial part in concrete. Past examinations demonstrates that the properties of RCA concrete are substandard in quality in contrasted with NCA concrete. This article endeavors to ponder the change in properties of RCA concrete with the expansion of mineral admixture named Alccofine. The exploratory examination was done to assess the change of the compressive quality of RCA concrete joining Alccofne. The Experimental investigation was carried out on six concrete mixes with a target characteristic strength of 30 MPa.Natural Coarse Aggregates were replaced by 25% and 50% of recycled Coarse Aggregates and Cement by 10% Alccofine. Compressive strength and Flexural Tensile Strength was found out. It was concluded that use of alccofine was advantageous in concrete made with recycled aggregates. Increase in compressive strength was observed by replacing cement with 10% Alccofine.","PeriodicalId":193668,"journal":{"name":"MatSciRN: Concrete (Topic)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129431607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical Strength of Admixed Conplast SP 430 Cement Paste and Concrete","authors":"A. Elinwa","doi":"10.2139/ssrn.3174640","DOIUrl":"https://doi.org/10.2139/ssrn.3174640","url":null,"abstract":"The objective of this research is in line with the continuous search for sustainable ways of producing cement paste and concrete. The work is an evaluation of the performance of Conplast SP 430 in Concrete. Dosage of 0.0 mL to 6.0 mL was used for the cement paste, and 0.0 mL to 7.6 mL, for the concrete specimens. A cement content of 380 kg/m3 and w/c ratio of 0.5 were used to which a dosage of 0.0 mL to 7.6 mL was administered in increment of 1.9 mL, and cured for 3 to 90 days in a laboratory water tank. The results showed good performance in terms of strength development. Dosages of 3.8 mL and 5.7 mL gave the best results. The results also showed that the material Conplast SP 430, is retarder and is good for hot weather concreting. However, the water absorption of the concrete specimens increased and thus, the work therefore recommends the use of a water reducer with the material. It is also suggested that further investigation on the WA of the admixture material should be done. The sensitivity analyses on the data generated on the compressive strength showed good agreement and very significant (p-value< 0.05).","PeriodicalId":193668,"journal":{"name":"MatSciRN: Concrete (Topic)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123724499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}