Utilization of Waste Glass Micro-particles in Producing Self-Consolidating Concrete Mixtures

Yasser Sharifi,Iman Afshoon,Zeinab Firoozjaei,Amin Momeni 한국콘크리트학회 2016 International Journal of Concrete Structures and M Vol.10 No.3

The successful completion of the present research would be achieved using ground waste glass (GWG) microparticles in self-consolidating concrete (SCC). Here, the influences of GWG microparticles as cementing material on mechanical and durability response properties of SCC are investigated. The aim of this study is to investigate the hardened mechanical properties, percentage of water absorption, free drying shrinkage, unit weight and Alkali Silica Reaction (ASR) of binary blended concrete with partial replacement of cement by 5, 10, 15, 20, 25 and 30 wt% of GWG microparticles. Besides, slump flow, V-funnel, L-box, J-ring, GTM screen stability, visual stability index (VSI), setting time and air content tests were also performed as workability of fresh concrete indicators. The results show that the workability of fresh concrete was increased by increasing the content of GWG microparticles. The results showed that using GWG microparticles up to maximum replacement of 15 % produces concrete with improved hardened strengths. From the results, when the amount of GWG increased there was a gradual decrease in ASR expansion. Results showed that it is possible to successfully produce SCC with GWG as cementing material in terms of workability, durability and hardened properties.

Lateral Torsional Buckling Capacity Assessment of Castellated Steel Beams Using Artifi cial Neural Networks

Yasser Sharifi,Mahmoud Hosseinpour,Adel Moghbeli,Hojjat Sharifi 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.5

A new model based on Artifi cial Neural Network (ANN) was established as a trustworthy technique for predicting ultimate lateral torsional buckling (LTB) capacity of castellated steel beams. The required information for training, validating and testing of the developed model obtained from a reliable database. Consequently, a new formulation based on the ANN has been off ered for predicting the failure load of castellated steel beams exposed to LTB. All parameters which may aff ect the LTB capacity of castellated beams were considered for presentation of this formula. Then, outcomes of the proposed formula were compared with predictions of Australian Standard (AS4100) for LTB capacity of castellated beams. This comparison indicated that proposed formula has a good performance for prediction of ultimate strength in castellated beams subjected to LTB. At the end, Garson’s algorithm has been established as a sensitivity analysis to determinate importance of each input in the proposed formula.

Utilization of Waste Glass Micro-particles in Producing Self-Consolidating Concrete Mixtures

Sharifi, Yasser,Afshoon, Iman,Firoozjaei, Zeinab,Momeni, Amin Korea Concrete Institute 2016 International Journal of Concrete Structures and M Vol.10 No.3

The successful completion of the present research would be achieved using ground waste glass (GWG) microparticles in self-consolidating concrete (SCC). Here, the influences of GWG microparticles as cementing material on mechanical and durability response properties of SCC are investigated. The aim of this study is to investigate the hardened mechanical properties, percentage of water absorption, free drying shrinkage, unit weight and Alkali Silica Reaction (ASR) of binary blended concrete with partial replacement of cement by 5, 10, 15, 20, 25 and 30 wt% of GWG microparticles. Besides, slump flow, V-funnel, L-box, J-ring, GTM screen stability, visual stability index (VSI), setting time and air content tests were also performed as workability of fresh concrete indicators. The results show that the workability of fresh concrete was increased by increasing the content of GWG microparticles. The results showed that using GWG microparticles up to maximum replacement of 15 % produces concrete with improved hardened strengths. From the results, when the amount of GWG increased there was a gradual decrease in ASR expansion. Results showed that it is possible to successfully produce SCC with GWG as cementing material in terms of workability, durability and hardened properties.

Structural Performance of Self-consolidating Concrete Used in Reinforced Concrete Beams

Yasser Sharifi 대한토목학회 2012 KSCE JOURNAL OF CIVIL ENGINEERING Vol.16 No.4

In recent years, an emerging technology termed Self-Consolidating Concrete (SCC) become popular in construction industry. A series of experimental tests carried out to investigate the structural behavior of SCC reinforced beams. A comparison between the experimental results and theoretical calculations based on the codes provisions has been also done. The beams have been made from concrete having average compressive strength of 30 MPa and reinforcement ratio (ρ /ρ b) in the range of 0.15-1.38. The ultimate moment for the tested beams was found to be about (0-7)% and (0-8)% higher than that of the predicted ultimate moment based on ACI 318 (05) and CSA (04) code provisions, adopted for reinforced beams cast with normal concrete vibrated into place,respectively. The test results on self-consolidating reinforced concrete beams showed that, the observed crack width under service loads were within acceptable limits.

Remaining Moment Capacity of Corroded Steel Beams

Yasser Sharifi,Reza Rahgozar 한국강구조학회 2010 International Journal of Steel Structures Vol.10 No.2

Steel structures are subjected to corrosion due to environmental exposure and inadequate maintenance. As a result, the carrying capacity and hence the level of safety of this structures diminishes with time due to accumulation of corrosion damage (e.g. section loss). For the assessment of the remaining moment capacity of corrosion damaged I-beams, two methods have been proposed in this paper based on the thickness loss data were compiled from four corroded damaged I-beams, namely the simple and accurate assessment methods. These methods give the quantitative relationship between the magnitude of structural defects (loss of thickness) and the corresponding remaining moment capacity (expressed as percentage of the as-new strength) of corrosion damaged beams. These methods require only the information regarding thickness loss of the appropriate elements of the members (flanges and web) and the capacity of the beam in its as-new condition, to assess the remaining moment capacity of a corrosion damaged beam. The thickness loss information can be provided by visual inspection or thickness measurement of a member. These assessment methods will help the practicing engineer to make a fast and reliable decision regarding the remaining moment capacity of corrosion damaged I-beam.

Buckling capacity of uniformly corroded steel members in terms of exposure time

Reza Rahgozar,Yasser Sharifi,Mohsen Malekinejad 국제구조공학회 2010 Steel and Composite Structures, An International J Vol.10 No.6

Most of steel structures in various industries are subjected to corrosion due to environmental exposure. Corrosion damage is a serious problem for these structures which may reduce their carrying capacity. These aging structures require maintenance and in many cases, replacement. The goal of this research is to consider the effects of corrosion by developing a model that estimates corrosion loss as a function of exposure time. The model is formulated based on average measured thickness data collected from three severely corroded I-beams (nearly 30 years old). Since corrosion is a time-dependent parameter. Analyses were performed to calculate the lateral buckling capacity of steel beam in terms of exposure time. Minimum curves have been developed for assessment of the remaining lateral buckling capacity of ordinary I-beams based on the loss of thicknesses in terms of exposure time. These minimum curves can be used by practicing engineers for better estimates on the service life of corrosion damaged steel beams.

A New Predictive Model for Restrained Distortional Buckling Strength of Half-through Bridge Girders using Artificial Neural Network

Sajjad Tohidi,Yasser Sharifi 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.4

Half-through girders are not affected by conventional lateral-torsional buckling. I-section beams of simply supported half-through girders experience compression in their top flanges and tension in their bottom flanges. In this condition, the compression flange is restrained only by the stiffness of the web, and the buckling mode is generally restrained distortional. In this study, new and efficient model is derived to predict the Restrained Distortional Buckling (RDB) strength of half-through I-section bridge girders utilizing an Artificial Neural Network (ANN). The model is developed based on a reliable database obtained from the nonlinear finite element (FE) method. To verify the accuracy of the derived model, it is applied to estimate the RDB strength of parts of the FE analysis results that were not included in the modeling process. A sensitivity analysis has been also developed to determine the importance of each input parameters. ANN model is further compared to the some existing design codes. The results indicate that the proposed model is effectively capable of evaluating the RDB load of the half-through girders. The prediction performance of the ANN model is markedly better than prediction of the AISC/LRFD and the AS4100 specifications. The ANN-based design equation can reliably be employed for pre-design applications.