This paper presents a theoretical model for flat cavity expansion in elastic soil. By using the conformal mapping method, the nonaxisymmetric boundary value problem of flat cavity expansion is transformed from the ori...
详细信息
Shrinkage Reducing Admixtures (SRAs) are increasingly being used in concrete as a method to minimize shrinkage and restrained shrinkage cracking. SRAs reduce shrinkage by decreasing the surface tension of the pore sol...
详细信息
ISBN:
(纸本)9781510831186
Shrinkage Reducing Admixtures (SRAs) are increasingly being used in concrete as a method to minimize shrinkage and restrained shrinkage cracking. SRAs reduce shrinkage by decreasing the surface tension of the pore solution;however, SRAs also impact the fluid viscosity, contact angle and density. Consequently, the absorption and desorption processes of cementitious systems containing SRA are altered. This paper describes experimental measurements of drying in cementitious mortar samples with and without SRAs, focusing on three components. First, solution properties (surface tension, viscosity, and contact angle) were measured at different temperatures. Second, the vapor desorption curves were measured and the non-linear moisture diffusion coefficient was quantified at different relative humidity (degrees of saturation). Third, neutron radiography measurements were performed to visualize and quantify the effect of the presence of SRA in solution on the moisture profiles and drying front generated during the early stages of the drying process. The results will be discussed in terms of theoretical observations in an effort to place the modeling of moisture and shrinkage gradients in concrete on a more fundamental footing.
One of the most popular trends in construction industry is sustainable construction. Therefore, application of construction materials with high insulation characteristics has significantly increased during the past de...
One of the most popular trends in construction industry is sustainable construction. Therefore, application of construction materials with high insulation characteristics has significantly increased during the past decade. Requirements for application of construction materials with high insulation parameters are required not only by means of energy saving and idea of sustainable construction but also by legislative requirements. Autoclaved aerated concrete (AAC) is a load bearing construction material, which has high heat insulation parameters. However, if the AAC masonry construction has high moisture content the heat insulation properties of the material decrease significantly. This fact lead to the necessity for the on-site control of moisture content in AAC in order to avoid inconsistency between the designed and actual thermal resistivity values of external delimiting constructions. Research of the impact of moisture content in AAC on its heat insulation properties has been presented in this paper.
The numerical analysis results of arched constructions are considered taking into account creep of the material. A typical building material substantially exhibiting creep under long-term loading is concrete. As a bas...
The numerical analysis results of arched constructions are considered taking into account creep of the material. A typical building material substantially exhibiting creep under long-term loading is concrete. As a basic model of concrete creep, a model of viscoelastic material was selected. The model was verified and calibrated on the experimental studies basis of concrete creep and in accordance with the requirements of regulatory documents. Numerical modeling of arches was carried out in the software environment of SIMULIA Abaqus.
Ordinary Portland Cement (OPC) has been used over the than hundred years for material construction especially as a binder in production of concrete. However, there are a few disadvantages with the using of OPC that ha...
详细信息
The best structural and mechanical characteristics are determined for the binders in diamond tools used in high-speed machining of grinding-wheel blanks. Prototype mills with curvilinear diamond bars of different desi...
详细信息
Broadband ultrasonic spectroscopy used to measure residual stresses in samples of high-temperature alloys. It is shown that the acoustoelasticity method and laser ultrasonic spectroscopy can be used to determine the d...
详细信息
Building Information Modeling(BIM)has been widely adopted in the building industry; however,the use of BIM in civil infrastructure facilities,sometimes referred to as civil Information Modeling(CIM),has been slow in i...
详细信息
Building Information Modeling(BIM)has been widely adopted in the building industry; however,the use of BIM in civil infrastructure facilities,sometimes referred to as civil Information Modeling(CIM),has been slow in its *** and academia are increasingly putting effort into CIM study and implementation,but so far there has been no comprehensive review of their efforts in this *** paper presents a framework to evaluate the current practices of CIM adoption for various civil infrastructure *** this study,civil infrastructure facilities were divided into nine categories for evaluation and the efforts with regard to CIM adoption for each infrastructure category were evaluated in six *** on the evaluation and comparison results of 171 case studies and 62 academic papers on CIM,research gaps were identified and recommendations were made.
Aswan High Dam Lake (AHDL) is the major freshwater body supplying Egypt with water used for various purposes. This paper aims to detect the better technique for extraction of the water surface of AHDL. Eight technique...
详细信息
Aswan High Dam Lake (AHDL) is the major freshwater body supplying Egypt with water used for various purposes. This paper aims to detect the better technique for extraction of the water surface of AHDL. Eight techniques are tested using Landsat ETM+ image and their performances in extracting the surface water area are evaluated. The eight techniques include Supervised and Unsupervised image classification techniques, Water Ratio Index [WRI], Normalized Difference Vegetation Index [NDVI], Normalized Difference Water Index [NDWI], Modified Normalized Difference Water Index [MNDWI], Automated Water Extraction Index [AWEI], and Normalized Difference Moisture Index [NDMI]. The results illustrate the effectiveness of the unsupervised technique, as it gave an overall accuracy about 99.91%. It is recommended to apply this technique in areas with similar conditions to efficiently extract the surface water areas from Landsat ETM+ data.
暂无评论