International Scientific Journal of Civil and Infrastructure Engineering (ISJCIE)
1- Combined Effects of Waste Glass and Nano-Silica Powder on Workability, Durability, and Mechanical Properties of Fiber-Reinforced Self-Compacting Mortar
Maryam Monazami, Shahrood University of Technology, Iran
Farshid Jandaghi Alaee, Shahrood University of Technology, Iran
Ashkan Abedian, Shahrood University of Technology, Iran
ABSTRACT: This research aims to combine the effects of waste glass and Nano-silica powder on the properties of fiber-reinforced self- compacting mortar. A detailed study was undertaken to investigate the effect of different glass powder contents as cement replacement on the behavior of mortar. For this purpose, Portland cement was partially replaced by 10%, 15%, and 20% waste glass powder alone, and then in combination with 2% substitution levels for Nano-silica. The amount of water-binder ratio and cementitious materials content were considered constant. Fresh properties of specimens were determined using slump flow, and v-funnel flow time tests, mechanical properties were determined by compressive strength, and tensile strength tests, and durability characteristics evaluated by water absorption, and resistance to sulfuric acid attack. Microstructural morphology of specimens was also assessed by scanning electron microscopy. It was observed that the workability slightly decreased and improved mechanical and durability properties could be achieved. The SEM micrographs illustrated more densified pore structure of the mortars containing waste glass powder which leads to increase in strength and durability of specimens.
Keywords: Waste glass; Nano-silica; Durability; Mechanical properties; Workability; Self-compacting mortar
2- Durability Plan for Coastline Concrete Structures and Design Considerations under Aggressive Environment Conditions
Tamur Salik, University of Technology, Sydney, Australia
Hadi Khabbaz, University of Technology, Sydney, Australia
ABSTRACT: Concrete durability is the ability of concrete to resist environmental impact or chemical attack in a long time without substantial deterioration. The aim of this study is to provide a durability plan for concrete structures to encompass the 100-year design life. The coastline concrete structure design requirements are formulated considering a case study of twin bridges in Ballina regions, Australia, which can be extended to other type of concrete structures. The proposed durability plan incorporates concrete strength, provided cover thickness and construction methods for each structural component. This paper elaborates the service life design of twin bridges and conducts durability design, employing the first principles for environmental loads affecting structural components. The realistic model for chloride induced corrosion, based on diffusion theory and carbon dioxide diffusion model, are also included in this study. In addition, the specifications of concrete and other preventive measures are described. The chloride modelling of the bridges has been conducted using a realistic model based on diffusion theory. It has been revealed that 100 years of design life can be achieved by using 65% slag in the concrete of bridge deck. The findings suggest that fibre boards and supplementary cementitious materials both are notably effective to maintain a durability of 100 years.
Keywords: Durability; Supplementary cementitious materials; Realistic modelling; Diffusion theory
3- ANN Model to Damage Detection of Steel Bridge Based on Signal Processing
Farzad Hatami, Amirkabir University of Technology (Tehran Polytechnic), Iran
ABSTRACT: Measurement uncertainties were regarded in this study through the overview of Gaussian white noise and axle load error into the numerically modeled accelerations before using them to train the systems. The result was discovered to be noise delicate, as predictable, but the method appears strong and performs well within typical noise levels. Furthermore, since white noise is a broadband contribution, construction modes of vibration that are untruth within its necessary bandwidth can be recognized from the output measurements. In this study, two frames, an un-damaged and a damaged steel bridge beam, were modeled to evaluate damage detection methods by white noise excitation. In the damaged frame of a steel bridge, one of the beams of the steel deck was weakened by a decrease in the modulus of elasticity. These frames were analyzed under the comparable record of the Tabas earthquake, and the displacement responses and acceleration of the classes were extracted. The results of the signal analysis and processing showed that the best indicator for evaluating the difference between the dynamic properties of the two frames and the damage detection is the ANN, since any damage, along with significant energy absorption at a specified frequency, can be varied. Also, the natural frequency of both structural was obtained by noise excitation with the ANN algorithm.
Keywords: ANN, Genetic Algorithm (GA), Damage Detection, White Noise Excitation
4- Numerical and Experimental Study on a Creative Concrete Pressure Reduction System (CPRS)
Saeed Nemati, Western Sydney University, Australia
Yahya Aliabadizadeh, University of Maryland, College Park, USA
Farzad Yaghmaei, Almasaze, UAE
ABSTRACT: The lateral pressure exerted on concrete structures formworks is influenced by various factors, including the aggregate content and size, water-to-cement ratio (w/c), type and amount of cement, presence of silica fume, fly ash, slag, ground limestone filler, type and quantity of superplasticizer, configuration of reinforcement steel bars, rate, and method of placement, concrete temperature, ambient conditions, set time of concrete, and the dimensions, type, rigidity, and roughness of the formwork. It can be challenging, and sometimes impossible, to simultaneously control all these parameters. This research introduces an innovative system called the Concrete Pressure Reduction System (CPRS), which incorporates sacrificial perforated sheets. The CPRS effectively manages the lateral pressure exerted by the concrete and mitigates excessive pressure on the formwork. Numerical modeling demonstrated that the utilization of this system can reduce the maximum principal stress, maximum shear stress, and maximum deformation by a minimum of approximately 27%, 30%, and 25%, respectively. Deformation obtained from parametric studies were verified through experimental tests, which displayed reasonable agreement with the outcomes of the study.
Keywords: Concrete Pressure Reduction System (CPRS), sacrificial perforated sheets, formwork