{"title":"Measurements of Breakdown and Buildup of Thixotropy in Cement Pastes Containing Diatomaceous Earth","authors":"Bashir Hasanzadeh, Zhihui Sun","doi":"10.32732/jcec.2023.12.2.100","DOIUrl":"https://doi.org/10.32732/jcec.2023.12.2.100","url":null,"abstract":"This paper proposes a comprehensive series of protocols that can make quantitative measurements on both breakdown and buildup aspects of thixotropic behaviors of cement pastes. While measuring breakdown and buildup separately, the correlations between these two aspects have also been investigated. Cement pastes with different water-to-binder ratios (w/b=0.4, 0.5 and 0.6) and different replacement levels of Diatomaceous Earth (DE) (0%, 2%, 6% and 10% by weight of cement) were studied. To simulate the real on-site conditions, parameters such as pressure and temperature were also considered during the measurement. The research found that increase in DE replacement dosage can reduce the energy required to breakdown thixotropic structure of cement pastes while no specific trend on buildup aspect was observed. Among the three used w/b ratios, the 0.5 w/b ratio has the most reduction effect in breakdown energy, where using 10% DE can lead to 65% of energy reduction in breakdown compared to the control sample. However, the measured yield stress for these specimens were very similar to each other. In addition, increase in temperature significantly increases the buildup ratio of cement pastes while increase in pressure as high as 20 MPa has a minimal impact on thixotropic properties of cement pastes. ","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125230234","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":"Assessment of the Combined Effect of Silica Fume, Fly Ash, and Steel Slag on the Mechanical Behavior of Concrete","authors":"Ovirup Basak Dipta, S. Sobhan, Aojoy Kumar Shuvo","doi":"10.32732/jcec.2023.12.2.78","DOIUrl":"https://doi.org/10.32732/jcec.2023.12.2.78","url":null,"abstract":"Every ton of cement produced emits half a ton of carbon dioxide, so there is an immediate need to limit cement use. Cementitious materials such as fly ash, silica fume, and steel slag can be substituted for cement in making concrete more rigid and stronger. This research work has been done to analyze the change in compressive strength in concrete, reducing the use of cement and coarse aggregate, in the case of varying percentages of cement replacement circumstances. To get this job done, there’s been conducted a variety of laboratory tests changing the partial cement replacement proportions with silica fume and fly ash and partial aggregate replacement with steel slag in the concrete mix. The test result showed that 15% silica fume, 10% fly ash, and 30% steel slag replacing proportion withstand more compressive load than the normal cement concrete mixture. The SEM test also supports the compressive strength test result by showing the internal bonding between the materials in the replaced binder-aggregate specimens. On the other hand, the flexural strength test came out with the best proportion of 15% cement replacement with fly ash and silica fume along with 10% coarse aggregate replacement with steel slag. The XRD patterns of the materials used also enumerate the standardization and testing procedures. The usage of sustainable cementitious materials like fly ash, silica fume, and steel slag incorporates the motivation behind reducing the industrial byproducts/wastes generated in such an amount that hampers our mother nature. The overall representation of this research will emancipate the initiatives taken toward greener and more sustainable construction.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134085737","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}
Ludovic Ivan Ntom Nkotto, Lionel Jacques Ntamag, Frances Jane Manjeh Ma-A, Judicaël Sandjong Kanda, J. V. Sontia Metekong
{"title":"Evaluation of Performances of Calcined Laterite and Oyster Shell Powder Based Blended Geopolymer Binders","authors":"Ludovic Ivan Ntom Nkotto, Lionel Jacques Ntamag, Frances Jane Manjeh Ma-A, Judicaël Sandjong Kanda, J. V. Sontia Metekong","doi":"10.32732/jcec.2023.12.2.86","DOIUrl":"https://doi.org/10.32732/jcec.2023.12.2.86","url":null,"abstract":"This work consisted in characterizing of calcined laterite and oyster shell powder based blended geopolymer binders. To do this, raw laterite taken from Soa in the city of Yaoundé and oyster shells extracted from Mouanko in the Sanaga-Maritime were initially air-dried, then dried at 105 °C, before being calcined at 500 °C and 200 °C respectively for 2 hours. These samples were subjected to preliminary studies, i.e. determination of their chemical and mineralogical compositions, particle size distributions, densities, as well as thermal analysis for the synthesis of geopolymer binders. X-ray diffractometry, thermal and gravimetric analysis were carried out on the oyster shell powder and laterite, in order to elucidate the time and degree of calcination of the two samples, the evolution of the linear shrinkage, the setting time as well as the compressive and flexural strengths of the geopolymer binders. The results obtained show that oyster shells are rich in CaCO3 and contain crystalline phases, while laterite is rich in silica, iron (FeCO3) and alumina (Al2O3). The geopolymer samples: Lat + 0% oyster shells have a setting time between 125 and 168 min for a compressive strength of about 47 MPa. The peak strength is observed around 15% addition of oyster shell powder, i.e. 53.5 MPa at 28 days with an increased setting time. This strength was decreased from 25 % of addition of oyster shells, despite the increase observed in the setting time. It appears from this study that the addition of 15% oyster shell increases the compressive strength of the geopolymer, but also leads to a considerable decrease in absorption rate. Above this rate, the compressive strength decreases drastically and concomitantly the setting time increases.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134070411","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":"Modelling Rainfall-Runoff Process of Kabul River Basin in Afghanistan Using ArcSWAT Model","authors":"Hamidullah Tani, G. Tayfur","doi":"10.32732/jcec.2023.12.1.1","DOIUrl":"https://doi.org/10.32732/jcec.2023.12.1.1","url":null,"abstract":"Kabul River Basin is the most populated and an important source of water resources in Afghanistan. The Soil and Water Assessment Tool (SWAT) model, together with the ArcGIS and SWAT-CUP, is employed to predict the runoff in the basin. Nine years of meteorological and hydrological data are employed in the study. The DEM, the soil cover, and the land use/cover data are downloaded from the available global database. The ArcGIS based soil classification, the land use/cover, the elevation, the drainage, and the slope distribution maps of the basin are generated. The meteorological data from 18 different stations and the hydrological data from 7 different stations are obtained from the Ministry of Energy and Water of Afghanistan. The basin is divided into 48 sub-basins with a total number of 770 hydrological response units (HRUs). The sensitivity analysis results revealed that the flow characteristics of KRB are highly influenced by the groundwater and snowmelt. The model is calibrated using the data from 2010 to 2014 and validated employing the data from 2015 to 2017 at seven different hydrological stations. The SWAT-CUP is successfully used to calibrate the model for predicting monthly and daily runoffs. The calibrations and validations for the seven stations are achieved, on the average, with the correlation coefficient (R) of 0.78 (for daily flows) and 0.82 (for monthly flows), respectively. Total water yield in the basin is estimated to be 432.9 mm/year, corresponding to 31 176 Mm3/year, hardly meeting the demand of 26 512 Mm3/year in the basin. ","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127986822","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":"Forecasting Flashover in a Compartment Fire by Using a Real-time Moving Average from Temperature Recordings","authors":"Amal Bouaoud, M. Lebey, Hui Wang, B. Manescau","doi":"10.32732/jcec.2023.12.1.55","DOIUrl":"https://doi.org/10.32732/jcec.2023.12.1.55","url":null,"abstract":"A series of flashover fire tests were carried out using standard wood as fuel with various ventilation, and a comprehensive set of experimental data is presented. Fighting against compartment fires with occurance of flashover could cause fatal consequences on firefighters. This work shows that the potential dangers as flashover can be detected as soon as possible thanks to the comparison between two moving averages in the past calculated from a temperature recording in a very short time. The present study aims to evaluate the possibility of using only commonly available measurements as data to be assimilated into the model. A real-time decision method is developed, allowing to the selection of optimal intervention to minimize firefight occupant exposure to the detected hazard. This approach includes the mathematical analysis which is based on the comparison of two moving averages centered in the past, calculated on the recordings of the smoke temperature. Firefighters would greatly benefit from this predictive method in real time, able to assist their decision making process during operations against a compartment fire. From the safety point of view, the model gives conservative predictions for flashover fire.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"24 5‐6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113955977","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}
R. Villarreal, A. Torres, Federico Aguayo, Carlos Moro
{"title":"An Alternative Test Method for Determining Hardened Air Void Parameters for Concrete Pavement","authors":"R. Villarreal, A. Torres, Federico Aguayo, Carlos Moro","doi":"10.32732/jcec.2023.12.1.19","DOIUrl":"https://doi.org/10.32732/jcec.2023.12.1.19","url":null,"abstract":"This research has developed an alternative test method for determining hardened air void parameters that follows ASTM C457 Procedure C, but does not require image analysis software or the required training and skills to develop or use one. Instead, the alternative technique uses a sophisticated microscope that has on-board counting and measuring capabilities, that are easy to use and easy to repeat. The technique was developed and tested on concrete mixtures with four target air void percentages (control at 2%, low at 3 – 5%, medium at 5 – 7%, and high at >8%) and compared to ASTM C457 Procedure A and B. The concrete produced was a conventional pavement mixture, which was a straight cement mixture with a target 3” slump. The results show that the alternative technique is not only just as accurate as the other methods, but it reduces the analysis time, human judgment calls, and the development and maintenance of a sophisticated image analysis program, which are all typical issues with any of the three procedures described in ASTM C457. Additionally, the alternative technique produces all hardened air void parameters that ASTM C457 provides. This study also demonstrates new potential issues that could result in erroneous hardened air void results when following ASTM C457. Lastly, this study provides a detailed description of the equipment necessary to produce the alternative method including a very detailed list of steps required to obtained the hardened air void parameters.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126795729","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}
A. Akinwande, O. Balogun, H. Danso, V. Romanovski, Akeem Oladele Ademati, Abiola Oluwasogo Oyediran
{"title":"Development of Insulating Masonry Bricks from Wood Fiber and Varying Milled Glass Proportion","authors":"A. Akinwande, O. Balogun, H. Danso, V. Romanovski, Akeem Oladele Ademati, Abiola Oluwasogo Oyediran","doi":"10.32732/jcec.2023.12.1.40","DOIUrl":"https://doi.org/10.32732/jcec.2023.12.1.40","url":null,"abstract":"Thermal efficient sandcrete bricks are masonry units with good thermal insulating properties. Wood fiber (WF) possesses low thermal conductivity, hence, its incorporation in mortar mix results in thermal efficient masonry units. Milled glass (MG) could be added for strength enhancement. This study incorporated WF into mortar mix at a constant dosage of 5 wt.%, with varying MG proportions of 0, 5, 10, 15 and 20 wt.% and cured for 7, 14 and 28 days. The results obtained showed minimization of porosity and water absorption at increasing MG content. Density and compressive strength were enhanced as MG content increased. Flexural and splitting tensile strengths appreciated and peaked at 15 wt.% MG. Thermal performance measured demonstrated progressive appreciation in thermal conductivity while specific heat capacity followed a downtrend as MG dosage increased. The study revealed that the collage of 5 wt. % wood fiber and 15 wt. % MG yielded optimum result. The study, therefore, concludes that the addition of milled glass and wood fiber positively and significantly affected the properties of sandcrete bricks. 15 wt.% of milled glass and 5% wood fiber inclusion in sandcrete bricks are recommended for use by construction practitioners.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130838214","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":"Response of Wave Dissipating Blocks Composing a Detached Breakwater to Waves with Various Periods","authors":"T. Kakinuma","doi":"10.32732/jcec.2022.11.4.189","DOIUrl":"https://doi.org/10.32732/jcec.2022.11.4.189","url":null,"abstract":"We discuss the response of the wave dissipating blocks composing a detached breakwater to the waves with various periods, based on both the experimental and numerical results. First, in the hydraulic experiments, the number of the blocks fallen by the irregular waves was the largest when the still water level is moderate, namely the HWL. When the large and long wave is incident, the overflow that lasted for a long time fell many blocks at the back of the breakwater. When the irregular waves, long wave, and irregular waves are continuously incident in this order, the first irregular wave train shifted several blocks, and the subsequent long wave dropped these shifted blocks, displacing the blocks around them, whereafter the second irregular wave train dropped many of the displaced blocks. Second, in the vertically two-dimensional calculations, when the long wave struck the breakwater, a large-scale vortex was created near the seabed in front of the breakwater and remained during the pushing wave. The overflow due to the long wave generated negative wave pressure at the top behind the breakwater. Based on both the numerical and experimental results behind the breakwater, when a large positive wave pressure is generated after a negative wave pressure that is not large in absolute value, the number of fallen blocks will reduce. When large and short waves cause overtopping, and negative wave pressure frequently appears behind a breakwater, the blocks at the back of the breakwater can gradually shift, loosening their engagement.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125080554","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":"Effect of Nanosilica and Carbon Nanotubes Addition on Mortar Mechanical and Durability Properties","authors":"Varisha Varisha, M. M. Zaheer, S. D. Hasan","doi":"10.32732/jcec.2022.11.4.210","DOIUrl":"https://doi.org/10.32732/jcec.2022.11.4.210","url":null,"abstract":"Nowadays, nanomaterials are being extensively used in civil engineering works for improving their quality. Improved compressive strength, flexural strength, modulus of elasticity, and good durability performance of nanocomposites attracted the researcher's interest in understanding these nanomaterials’ behavior in cementitious composites. In the present paper, mechanical and durability properties of 1.0 wt% nanosilica (NS) and four different types of 0.3 wt% carbon nanotubes (CNTs) admixed cement mortar was assessed at 28, 56, 90 and 120 days under sulphate water curing. The outside diameters of CNTs are 10-20 nm and 30-50 nm, each type are un-treated and treated with COOH group, respectively. Results showed that flexural and compressive strength was improved for mortar sample admixed with nanomaterials than normal one. Also, nanomaterials came up as a good solution against abrasion and sulphate attacks. The durability is also enhanced for such mortar samples as the density increases, reducing the porosity and water absorption capacity. Resistivity results indicated negligible to low risk of corrosion, thus increasing the durability of these mortar samples. Overall, the sample formed with treated CNTs and 30nm – 50nm outside diameter gave better results than control specimen and other admixed mortar. Scanning Electron Microscopic images were in strong correlation with the experimental results.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114280280","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}
Annette Dahlhoff, B. Winkels, Cynthia Morales Cruz, M. Raupach
{"title":"Investigations on the Experimental Setup for Testing the Centric Tensile Strength According to ASTM C307 of Mineral-based Materials","authors":"Annette Dahlhoff, B. Winkels, Cynthia Morales Cruz, M. Raupach","doi":"10.32732/jcec.2022.11.4.239","DOIUrl":"https://doi.org/10.32732/jcec.2022.11.4.239","url":null,"abstract":"Centric tensile tests often exhibit high standard deviations due to various factors, hence various test setups have been developed in the past. Based on the specifications in ASTM C307-18, the experimental setup was further developed to reduce the standard deviation resulting from the test setup itself and thus to obtain reliable, reproducible test results. Furthermore, it has been investigated, whether the test setup is suitable for materials of low strength. In the further developed experimental setup three mineral-based materials with tensile strengths in the range of 0.4 to 5.9 MPa were examined and compared to ASTM C307-18. For this purpose, the optical 3D-measurement system ARAMIS® and a positioning adapter designed for the specimen geometry were used to validate and verify the developed experimental setup and to ensure a consistent position of the specimen. For the low strength mineral-based materials tensile strength tests could be implemented and recommendations for the test parameters test speed, preload and required number of specimens could be developed.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128754852","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}