Pub Date : 2020-12-01DOI: 10.1515/SSPJCE-2020-0026
I. Demjan, M. Tomko, R. Soltys
The aim of this paper was to estimate further service possibilities of precast concrete structure. It was necessary to remain basic reliability conditions for actual service conditions. To reach this goal a complex experimental diagnostics and structural analysis was applied. On the basis of these methods construction arrangements recommendations were defined.
{"title":"Structural diagnostics and structural analysis of precast concrete building","authors":"I. Demjan, M. Tomko, R. Soltys","doi":"10.1515/SSPJCE-2020-0026","DOIUrl":"https://doi.org/10.1515/SSPJCE-2020-0026","url":null,"abstract":"\u0000 The aim of this paper was to estimate further service possibilities of precast concrete structure. It was necessary to remain basic reliability conditions for actual service conditions. To reach this goal a complex experimental diagnostics and structural analysis was applied. On the basis of these methods construction arrangements recommendations were defined.","PeriodicalId":30755,"journal":{"name":"Selected Scientific Papers Journal of Civil Engineering","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83967246","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}
Abstract The building industry has been one of the fast-growing sectors in Rwanda, and multiple residential houses with amazing pitched roofs are being implemented in different cities. As the country is very hilly, the influence of wind loads on the buildings is high and therefore the selection step of roof slopes needs to be carefully undertaken, in order to ensure not only the structure safety, but also the economy. Available international and national guidelines give details about safety and functionality requirements, but don’t talk much about economic aspect, and this was the purpose of the given study. Using a well elaborated methodology, the influence of the roof slope on its cost was checked, and it was established that the slope’s increase of one degree would raise the roof cost by 3.6%. Therefore, during the roof slope selection and design process, economic requirements need more attention.
{"title":"Effect of the Roof Slope on the Cost Variation of Residential Houses","authors":"Leopold Mbereyaho, Doris Daniella Dusabe Minani, Alain Niyonshuti, Yvan Coppens Nsenga","doi":"10.1515/sspjce-2020-0009","DOIUrl":"https://doi.org/10.1515/sspjce-2020-0009","url":null,"abstract":"Abstract The building industry has been one of the fast-growing sectors in Rwanda, and multiple residential houses with amazing pitched roofs are being implemented in different cities. As the country is very hilly, the influence of wind loads on the buildings is high and therefore the selection step of roof slopes needs to be carefully undertaken, in order to ensure not only the structure safety, but also the economy. Available international and national guidelines give details about safety and functionality requirements, but don’t talk much about economic aspect, and this was the purpose of the given study. Using a well elaborated methodology, the influence of the roof slope on its cost was checked, and it was established that the slope’s increase of one degree would raise the roof cost by 3.6%. Therefore, during the roof slope selection and design process, economic requirements need more attention.","PeriodicalId":30755,"journal":{"name":"Selected Scientific Papers Journal of Civil Engineering","volume":"72 1","pages":"89 - 102"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78772382","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}
Pub Date : 2020-09-01DOI: 10.1515/sspjce-2020-0011
C. Aribi, Aissa Bouaissi, B. Safi, M. Saidi
Abstract This paper presents an experimental investigation on the post-repair flexural response of mortars with and without damage. In order to improve the mechanical properties of the damaged mortars, which were subjected to different loads ranging between 40 % and 90 %, the mortars specimens were reinforced and repaired using two different composite materials, the first with only epoxy resin, while the second consisted of a mixture of epoxy resin and glass fiber. The results show a significant improvement in the stiffness damaged. Therefore, the reinforced specimens by a layer of resin on the lower side surface increased the bending strength by 58 %, when compared to those control samples. The reinforcement using composite resin-fiber of glass exhibited considerable increases in the safety of constructions. The SEM images of damaged samples with and without repair, revealed the impact of reinforced glass fibers-mortar on the matrix-mortar by improving theirs mechanical performances.
{"title":"An experimental study on damaged cementitious mortars repaired by glass/epoxy composite materials","authors":"C. Aribi, Aissa Bouaissi, B. Safi, M. Saidi","doi":"10.1515/sspjce-2020-0011","DOIUrl":"https://doi.org/10.1515/sspjce-2020-0011","url":null,"abstract":"Abstract This paper presents an experimental investigation on the post-repair flexural response of mortars with and without damage. In order to improve the mechanical properties of the damaged mortars, which were subjected to different loads ranging between 40 % and 90 %, the mortars specimens were reinforced and repaired using two different composite materials, the first with only epoxy resin, while the second consisted of a mixture of epoxy resin and glass fiber. The results show a significant improvement in the stiffness damaged. Therefore, the reinforced specimens by a layer of resin on the lower side surface increased the bending strength by 58 %, when compared to those control samples. The reinforcement using composite resin-fiber of glass exhibited considerable increases in the safety of constructions. The SEM images of damaged samples with and without repair, revealed the impact of reinforced glass fibers-mortar on the matrix-mortar by improving theirs mechanical performances.","PeriodicalId":30755,"journal":{"name":"Selected Scientific Papers Journal of Civil Engineering","volume":"16 1","pages":"113 - 128"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85069063","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}
Pub Date : 2020-09-01DOI: 10.1515/sspjce-2020-0005
P. Nagy, M. Zeleňáková
Abstract In recent times, extremely dry seasons have been occurring more and more often in the eastern Slovakia, alternating with extremely wet seasons like torrential floods from extreme rainfall. Trend of reconnaissance drought index (RDI) and streamflow drought index (SDI) was evaluated in the paper using the Mann-Kendall test. The indices were evaluated at six climatic and river stations in the eastern Slovakia. The Mann-Kendal test results showed that the trend in the SDI index is not significant in 5 stations and only in one station the trend is significant. In the RDI index the trend is not significant in four stations and the trend is significant in two stationshe abstract is to indicate the subject of the paper, how the author proposes to develop the subject and its overall objective, aim or outcome.
{"title":"Drought indices and trend analysis","authors":"P. Nagy, M. Zeleňáková","doi":"10.1515/sspjce-2020-0005","DOIUrl":"https://doi.org/10.1515/sspjce-2020-0005","url":null,"abstract":"Abstract In recent times, extremely dry seasons have been occurring more and more often in the eastern Slovakia, alternating with extremely wet seasons like torrential floods from extreme rainfall. Trend of reconnaissance drought index (RDI) and streamflow drought index (SDI) was evaluated in the paper using the Mann-Kendall test. The indices were evaluated at six climatic and river stations in the eastern Slovakia. The Mann-Kendal test results showed that the trend in the SDI index is not significant in 5 stations and only in one station the trend is significant. In the RDI index the trend is not significant in four stations and the trend is significant in two stationshe abstract is to indicate the subject of the paper, how the author proposes to develop the subject and its overall objective, aim or outcome.","PeriodicalId":30755,"journal":{"name":"Selected Scientific Papers Journal of Civil Engineering","volume":"229 1","pages":"39 - 45"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80227680","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}
Pub Date : 2020-09-01DOI: 10.1515/sspjce-2020-0003
T. Baroš, D. Katunský
Abstract This paper could be considered as a general overview of current examples of realization, research, in architecture which could be called parasitic. Also, as an outline of possible new perspectives on current issues through the biomimicry design philosophy. The aim was also to clearly articulate the intent of the research I am dealing with while opening up a discourse on the subject.
{"title":"Parasitic architecture","authors":"T. Baroš, D. Katunský","doi":"10.1515/sspjce-2020-0003","DOIUrl":"https://doi.org/10.1515/sspjce-2020-0003","url":null,"abstract":"Abstract This paper could be considered as a general overview of current examples of realization, research, in architecture which could be called parasitic. Also, as an outline of possible new perspectives on current issues through the biomimicry design philosophy. The aim was also to clearly articulate the intent of the research I am dealing with while opening up a discourse on the subject.","PeriodicalId":30755,"journal":{"name":"Selected Scientific Papers Journal of Civil Engineering","volume":"18 1","pages":"19 - 28"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89388563","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}
Pub Date : 2020-09-01DOI: 10.1515/sspjce-2020-0010
M. Bouali
Abstract The exact concentration of the stress generated by the presence of a cavity is a problem of great significance in Mining and Civil Engineering. An interesting stress concentration problem is the biaxial one. A numerical analysis of stress around a cylindrical hole in an infinite elastic medium under opposite biaxial loading was investigated. This far-field loading is equivalent to a pure shear loading on planes rotated 45°. Analysis consisted of two-dimensional finite-difference computations carried out with the Fast Lagrangian of Continua (FLAC) code. The Stress Concentration Factor (SFC) is evaluated numerically and compared with the existing solution. Predicted results of stress distribution around the hole were found in good agreement with the analytic theory.
{"title":"Numerical Modeling of Hole Under Opposite Biaxial Loadings","authors":"M. Bouali","doi":"10.1515/sspjce-2020-0010","DOIUrl":"https://doi.org/10.1515/sspjce-2020-0010","url":null,"abstract":"Abstract The exact concentration of the stress generated by the presence of a cavity is a problem of great significance in Mining and Civil Engineering. An interesting stress concentration problem is the biaxial one. A numerical analysis of stress around a cylindrical hole in an infinite elastic medium under opposite biaxial loading was investigated. This far-field loading is equivalent to a pure shear loading on planes rotated 45°. Analysis consisted of two-dimensional finite-difference computations carried out with the Fast Lagrangian of Continua (FLAC) code. The Stress Concentration Factor (SFC) is evaluated numerically and compared with the existing solution. Predicted results of stress distribution around the hole were found in good agreement with the analytic theory.","PeriodicalId":30755,"journal":{"name":"Selected Scientific Papers Journal of Civil Engineering","volume":"13 1","pages":"103 - 112"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78987969","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}
Pub Date : 2020-09-01DOI: 10.1515/sspjce-2020-0008
E. K. Burdová, S. Vilčeková, P. Kapalo
Abstract An occurrence of indoor particulate matters largely depends on outdoor pollution and its transportation indoors as well as on the presence of indoor pollution sources. Pollutants can flow from outdoor to indoor or indoor to outdoor under various conditions e.g. contribution of indoor pollutants to outdoor (in rural location with biomass fuel used for cooking) or outdoor to indoor in urban locations. This study aims to carry out an experimental investigation of particulate matter (PM) concentrations, temperature, humidity and air velocity during three days in winter season in Košice-Sever, Slovakia. Values of outdoor PM10 concentrations ranged from 12.58 μg/m3 to 6,627.51 μg/m3. Extremely high concentrations of PM10 were found near the traffic. Outdoor mean value of PM2.5 (21.82 μg/m3) did not exceed a permissible value of 25 μg/m3. Overloads by PM10 concentrations denote almost 108% and 2,270%. The indoor/outdoor (I/O) ratio was <1 for all fractions of particulate matters.
{"title":"Indoor and Outdoor Measurements of Particulate Matter Concentrations: A Case Study Košice-Sever, Slovakia","authors":"E. K. Burdová, S. Vilčeková, P. Kapalo","doi":"10.1515/sspjce-2020-0008","DOIUrl":"https://doi.org/10.1515/sspjce-2020-0008","url":null,"abstract":"Abstract An occurrence of indoor particulate matters largely depends on outdoor pollution and its transportation indoors as well as on the presence of indoor pollution sources. Pollutants can flow from outdoor to indoor or indoor to outdoor under various conditions e.g. contribution of indoor pollutants to outdoor (in rural location with biomass fuel used for cooking) or outdoor to indoor in urban locations. This study aims to carry out an experimental investigation of particulate matter (PM) concentrations, temperature, humidity and air velocity during three days in winter season in Košice-Sever, Slovakia. Values of outdoor PM10 concentrations ranged from 12.58 μg/m3 to 6,627.51 μg/m3. Extremely high concentrations of PM10 were found near the traffic. Outdoor mean value of PM2.5 (21.82 μg/m3) did not exceed a permissible value of 25 μg/m3. Overloads by PM10 concentrations denote almost 108% and 2,270%. The indoor/outdoor (I/O) ratio was <1 for all fractions of particulate matters.","PeriodicalId":30755,"journal":{"name":"Selected Scientific Papers Journal of Civil Engineering","volume":"83 1","pages":"77 - 88"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91021711","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}
Pub Date : 2020-09-01DOI: 10.1515/sspjce-2020-0004
A. Repel, M. Zeleňáková, V. Jothiprakash, H. Hlavatá, S. Gałaś, M. M. Portela
Abstract Short-term heavy rains are one the most important rains from a meteorological, hydrological, and also technical point of view. When designing rainwater drainage systems or rainwater management systems, the intensity of short-term rains is used as a design parameter, because of short-term rains usually reach the highest intensity. This paper is focused on analysis of short-term heavy rains occurrence in the last 15 years in 3 rainfall stations in eastern Slovakia. The data used in analysis are automatically collected 10-minute precipitation totals at rainfall stations Poprad, Kamenica nad Cirochou and Košice.
{"title":"Analysis of short – term heavy rains in eastern Slovakia in the period 2003 - 2018","authors":"A. Repel, M. Zeleňáková, V. Jothiprakash, H. Hlavatá, S. Gałaś, M. M. Portela","doi":"10.1515/sspjce-2020-0004","DOIUrl":"https://doi.org/10.1515/sspjce-2020-0004","url":null,"abstract":"Abstract Short-term heavy rains are one the most important rains from a meteorological, hydrological, and also technical point of view. When designing rainwater drainage systems or rainwater management systems, the intensity of short-term rains is used as a design parameter, because of short-term rains usually reach the highest intensity. This paper is focused on analysis of short-term heavy rains occurrence in the last 15 years in 3 rainfall stations in eastern Slovakia. The data used in analysis are automatically collected 10-minute precipitation totals at rainfall stations Poprad, Kamenica nad Cirochou and Košice.","PeriodicalId":30755,"journal":{"name":"Selected Scientific Papers Journal of Civil Engineering","volume":"75 1","pages":"29 - 37"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77532622","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}
Pub Date : 2020-09-01DOI: 10.1515/sspjce-2020-0006
A. Sičáková, Erika Figmigová, M. Špak
Abstract Currently, the consumption of blended cements is increasing all over the world. This is due to environmental, technical and economic reasons. Among the additives mixed with ordinary Portland cement, ground granulated blast furnace slag and fly ash are of particular significance. However, some regions may lack standard additives, and vice versa, may be rich in natural pozzolans. This paper is focused on the perlite as a natural pozzolanic material which is locally available. This study presents the results of the application of perlite as a component of blended cements in different proportions, representing binary and ternary compositions, and compares it with standard additives (fly ash and ground granulated blast furnace slag). The time development of both compressive and flexural strength, including results of 2, 7, 28 and 90-day testing, is analyzed. Perlite binders show acceptable time development of strengths, which is comparable to conventional blended binders based on ground granulated blast furnace slag and fly ash and do not constitute a technological barrier. With a higher dose of perlite, the time increase in flexural strength is slower, but the rate of increase in compressive strength does not change substantially. Flexural strength of 4.1–6.2 MPa and compressive strength of 18.8–38.5 MPa are sufficient for a number of practical applications and are expected to meet the required limits. An improvement of strengths in the later period (90 days) was also confirmed.
{"title":"Comparison of the strength development of binary and ternary cements containing perlite powder","authors":"A. Sičáková, Erika Figmigová, M. Špak","doi":"10.1515/sspjce-2020-0006","DOIUrl":"https://doi.org/10.1515/sspjce-2020-0006","url":null,"abstract":"Abstract Currently, the consumption of blended cements is increasing all over the world. This is due to environmental, technical and economic reasons. Among the additives mixed with ordinary Portland cement, ground granulated blast furnace slag and fly ash are of particular significance. However, some regions may lack standard additives, and vice versa, may be rich in natural pozzolans. This paper is focused on the perlite as a natural pozzolanic material which is locally available. This study presents the results of the application of perlite as a component of blended cements in different proportions, representing binary and ternary compositions, and compares it with standard additives (fly ash and ground granulated blast furnace slag). The time development of both compressive and flexural strength, including results of 2, 7, 28 and 90-day testing, is analyzed. Perlite binders show acceptable time development of strengths, which is comparable to conventional blended binders based on ground granulated blast furnace slag and fly ash and do not constitute a technological barrier. With a higher dose of perlite, the time increase in flexural strength is slower, but the rate of increase in compressive strength does not change substantially. Flexural strength of 4.1–6.2 MPa and compressive strength of 18.8–38.5 MPa are sufficient for a number of practical applications and are expected to meet the required limits. An improvement of strengths in the later period (90 days) was also confirmed.","PeriodicalId":30755,"journal":{"name":"Selected Scientific Papers Journal of Civil Engineering","volume":"87 1","pages":"47 - 57"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79372788","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}
Pub Date : 2020-09-01DOI: 10.1515/sspjce-2020-0012
Lynda Kheddache, K. Chahour, B. Safi
Abstract The purpose of this work is to assess the steel fiber distribution effect on physical and mechanical properties of self-compacting mortar. An experimental study was conducted to see the fiber distribution during the implementation of self-compacting mortars that are fluid and on mechanical behavior in bending tensile strength. A method of placing self-compacting mortar in the molds has been developed to highlight the distribution of fibers in the cementitious matrix. The mortars are placed in prismatic molds in three layers. The amount of steel fibers differs from one layer to another. A total quantity of 90 kg /m3 was distributed in prismatic molds of dimensions 40x40x160 mm3. Straight and hooked ends steel fibers were used. The characteristics of mortars containing both types of fibers in the fresh and hardened state were measured and compared to those of self-compacting mortar without fibers. The pouring by layer allowed us to deduce that the distribution of metallic fibers has a significant effect on the hardened properties of the mortar. Indeed, the mechanical strength of the fiber-reinforced mortar depends on the nature and distribution of fibers in the cementitious matrix (mortar). A gain in bending tensile strength of 71.83% was recorded for self-compacting mortars elaborated with hooked end fibers and 52.11% for those containing straight steel fibers. Indeed, mortars containing entirely the same dosage of steel fibers (90 kg/m3) have a bending tensile strength that varies according to the fibers dosage by layers. Mortar samples with higher fiber content in the lower layer have a higher bending tensile strength than other samples with a higher fiber layer in the middle or layer above. However, it should be noted that steel fibers with hooks are much more effective than those without hooks. Indeed, the effect of fiber distribution is more significant for fibers without hooks because the hooks can slow down the movement of the fibers during the pouring of the mortar. The variation of the dosages per layer generated a difference in the deflection values for the mortars. The deflection is much higher for fiber-reinforced mortars (with hooks) compared to fiber-reinforced mortars without hooks.
摘要本文旨在研究钢纤维分布对自密实砂浆物理力学性能的影响。通过试验研究了自密实砂浆在流体状态下的纤维分布及其弯曲抗拉强度的力学性能。开发了一种在模具中放置自密实砂浆的方法，以突出纤维在胶凝基质中的分布。迫击炮分三层放置在棱柱形模具中。钢纤维的含量因层而异。在尺寸为40x40x160 mm3的棱柱形模具中分布的总数量为90 kg /m3。直端和钩端使用钢纤维。测定了含两种纤维的自密实砂浆在新鲜和硬化状态下的特性，并与不含纤维的自密实砂浆进行了比较。通过分层浇筑，我们推断出金属纤维的分布对砂浆的硬化性能有显著影响。实际上，纤维增强砂浆的机械强度取决于胶凝基质(砂浆)中纤维的性质和分布。结果表明，端部掺有钩型钢纤维的自密实砂浆的抗弯强度提高了71.83%，端部掺有直型钢纤维的自密实砂浆的抗弯强度提高了52.11%。事实上，含有完全相同剂量的钢纤维(90kg /m3)的砂浆具有弯曲拉伸强度，该强度根据纤维的分层剂量而变化。下层纤维含量较高的砂浆试样，其抗弯抗拉强度高于中层或上层纤维含量较高的砂浆试样。但需要注意的是，带钩的钢纤维比不带钩的钢纤维效果要好得多。事实上，纤维分布的影响对于没有吊钩的纤维更为显著，因为在砂浆浇注过程中，吊钩可以减缓纤维的运动。每层剂量的变化产生了砂浆挠度值的差异。与不带钩的纤维增强迫击炮相比，带钩的纤维增强迫击炮的挠度要高得多。
{"title":"Effect of Fiber Distribution on the Mechanical Behavior in Bending of Self-Compacting Mortars","authors":"Lynda Kheddache, K. Chahour, B. Safi","doi":"10.1515/sspjce-2020-0012","DOIUrl":"https://doi.org/10.1515/sspjce-2020-0012","url":null,"abstract":"Abstract The purpose of this work is to assess the steel fiber distribution effect on physical and mechanical properties of self-compacting mortar. An experimental study was conducted to see the fiber distribution during the implementation of self-compacting mortars that are fluid and on mechanical behavior in bending tensile strength. A method of placing self-compacting mortar in the molds has been developed to highlight the distribution of fibers in the cementitious matrix. The mortars are placed in prismatic molds in three layers. The amount of steel fibers differs from one layer to another. A total quantity of 90 kg /m3 was distributed in prismatic molds of dimensions 40x40x160 mm3. Straight and hooked ends steel fibers were used. The characteristics of mortars containing both types of fibers in the fresh and hardened state were measured and compared to those of self-compacting mortar without fibers. The pouring by layer allowed us to deduce that the distribution of metallic fibers has a significant effect on the hardened properties of the mortar. Indeed, the mechanical strength of the fiber-reinforced mortar depends on the nature and distribution of fibers in the cementitious matrix (mortar). A gain in bending tensile strength of 71.83% was recorded for self-compacting mortars elaborated with hooked end fibers and 52.11% for those containing straight steel fibers. Indeed, mortars containing entirely the same dosage of steel fibers (90 kg/m3) have a bending tensile strength that varies according to the fibers dosage by layers. Mortar samples with higher fiber content in the lower layer have a higher bending tensile strength than other samples with a higher fiber layer in the middle or layer above. However, it should be noted that steel fibers with hooks are much more effective than those without hooks. Indeed, the effect of fiber distribution is more significant for fibers without hooks because the hooks can slow down the movement of the fibers during the pouring of the mortar. The variation of the dosages per layer generated a difference in the deflection values for the mortars. The deflection is much higher for fiber-reinforced mortars (with hooks) compared to fiber-reinforced mortars without hooks.","PeriodicalId":30755,"journal":{"name":"Selected Scientific Papers Journal of Civil Engineering","volume":"10 1","pages":"129 - 148"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88113369","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}
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