الفهرس 
Literature ReviewOnly 14 pages are availabe for public view
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Abstract
Reactive Powder Concrete (RPC) is considered to be one of the innovated types of high strength concrete in the construction industry that is developed in the 90’s. RPC shows an advanced and powerful behavior compared to that of the ordinary concrete. Despite the popularity of RPC and being widely known nowadays, its production is still limited in many countries as well as Egypt due to the lack of existence for many of its constituent materials, in addition to the high prices and the unsustainable used materials.
Silica fume (SF) is considered an essential constituent in the production of RPC due to its high amorphous silica content. Additionally, development of RPC requires a high cement demand. Cement production is not a sustainable eco-friendly process. This research studies the impact of using metakaoline (MK) as an available alternative pozzolans to replace silica fume (SF) in the development of RPC in Egypt. The influence of incorporating nano materials in RPC is also investigated. Also, this work evaluates the performance of RPC developed by Alkali Activated Materials (AAM) to replace the utilization of cement with partially or totally environmentally friendly Alkali Activated Materials (AAM) binders. Different curing techniques have been used by considering the most appropriate method for each mix.
An experimental program and an analytical program have been executed in this study. The experimental program consists of three phases. The first phase (I-E) is designed to study the impact of using metakaoline (MK) as an available alternative pozzolans to replace silica fume (SF) in the development of RPC in Egypt. The influence of incorporating nano materials in RPC is also investigated. Different curing techniques were applied on eleven different mixes to evaluate the compressive strength, sorptivity, elastic modulus. The considered curing regimes in this part are water curing, steam curing, and autoclave curing.
The second phase (II -E) analyses the engineering properties of developing RPC based AAS (Alkali Activated Slag) under different curing regimes with substitution percent of cement by (0, 15% and 100%). This experimental phase is carried out in order to assign the performance of eight different mixes in respect to the mechanical properties (compressive, elastic modulus) and in respect to durability (sorptivity and absorption). The considered curing regimes in this part are; air curing, heat curing, and microwave curing.
The third experimental phase (III-E) is designed to investigate the behavior of RPC structural beams manufactured from RPC under three-point load. The initial cracking loads, failure loads, and the load deflection curves were recorded. from the executed experimental program, RPC is successfully developed using metakaoline as an available local material in Egypt RPC with replacement up to 50%. Adding nano materials to RPC based metakoline mixes could redeem the properties of RPC. Autoclave curing significantly promotes RPC mixes to early reach its maximum strength at by accelerating the pozzolanic reaction. from the adopted experimental program in phase (II-E), it was found that slag attained satisfied results in the behaviour of RPC based Alkali Activated Materials as a total cement replacement and a sustainable eco-friendly material. Microwave curing is considered a better choice than conventional curing in RPC based Alkali Activated Materials due to the activation of the polymerization process.
The analytical program carried in this work consists of four phases. The first phase (I-A) is designed to predict a proposed modified equation for calculating ultimate load for RPC beams. The second phase (II-A) is designed to perform finite element analysis (FEA) using ABAQUS software to investigate the behavior of six RPC beams in which concrete damaged plasticity model (CDP) is adapted to simulate the material behaviour of modified RPC. The material properties are deduced from the material tests executed on the specimens of six designed RPC mixes through the compressive strength test and the modulus of elasticity test, that were then utilized as the input for CDP model. The load deflection behavior of the beams subjected to three-point loads was analysed and then FEA results have been compared with the experimental results of the RPC beams to verify the validation of the numerical model. It was observed that the analytical results were in good agreement with the experimental results.
The third phase (III-A) is designed to verify the validation of the executed numerical model with experimental executed beams in literature. It was found that there is good agreement with the numerical model. The fourth phase (IV-A) is designed to perform an analytical investigation to find out the influence of other parameters as amount of reinforcing steel on the behavior of RPC beams. The proposed model can be used to conduct parametric study for various RPC elements. Provided with reasonable accuracy, it can be concluded that the developed finite element model can well predict the structural performance of RPC beams.
Finally, a comparative study is carried out for the production and repair cost estimation for RPC to exhibit the effectiveness of applying RPC based cement and RPC based geopolymer for concrete members considering the long-life cycle of a building. It was observed that the excellent durability properties would significantly decrease the maintenance costs and increase the service life of RPC members.