Effect of reinforcement and pre-stressing force oın ASR expansion

Download

index.pdf

Date

2012

Author

Musaoğlu, Orhan

Metadata

Show full item record

Item Usage Stats

230
views

82
downloads

Alkali Silica Reaction in concrete is a chemical deterioration process occurring between alkalis in cement paste and reactive aggregates. ASR increases expansion and cracking as well as other durability problems such as freezing and thawing. It is most probable that concrete structure will collapse unless mechanical, mineral, or chemical preventive measures are taken against ASR or this problem is realized and solved in the design stage of the concrete structure or later on. Rather than ordinary preventive measures in which mineral admixtures are used, mechanical ones were investigated in this study. In the experiment done by using the accelerated mortar bar method, reinforced concrete specimens on which pre-stressing force was applied were examined. The effects of reinforcement ratio and pre-stressing force on ASR based expansion and cracking were studied. Expansion and cracking developments in time were followed, and the connection between these phenomena and the energy produced by ASR was made. By applying the same mechanical preventive measures on the specimens prepared by using different reactive aggregates, the effectiveness of these methods with respect to the degree of v ASR was investigated. Also, the methods in question were compared with traditional preventive measures (fly ash). The investigation results show that reinforcement and pre-stressing force play a significant role in diminishing the effects of ASR.Keywords:Alkali-Silica Reaction, Reinforced Concrete Specimen, Pre-stressed Concrete, Mechanical Preventive Measures, Energy of ASR

Subject Keywords

Reinforced concrete., Reinforced concrete, Prestressed concrete., Prestressed concrete construction., Alkali Silica reaction.

URI

http://etd.lib.metu.edu.tr/upload/12614872/index.pdf
https://hdl.handle.net/11511/21969

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Effect of alkali-silica reaction expansion on mechanical properties of concrete Hafçı, Alkan; Turanlı, Lütfullah; Department of Civil Engineering (2013) Alkali-silica reaction (ASR) is a chemical deterioration process which arises in concrete due to reactive aggregate from its constituent, sufficient alkalis from cement or external resources and humidity about 85%. ASR gel, formed by the reaction, absorbs water and expands so that it causes expansion and cracking in concrete. ASR has detrimental effects on mechanical properties of concrete. Therefore, ASR which is a long and a constantly progressive reaction may become a threat to the safety of concrete str...
Effect of triisopropanol amine and calcium nitrate on the strength development of glass fiber reinforced concrete t Alkılıç, Mustafa Onur; Yaman, İsmail Özgür; Öztürk, Abdullah; Department of Cement Engineering (2015) This thesis work aims to research the possibility of acceleration in strength development by the use of Calcium Nitrate (Ca(NO3)2) and Triisopropanol Amine (TIPA) in the production of glass fiber reinforced concrete, also known as GFRC or GRC. In conventional cementitious systems, Ca(NO3)2 is used as an accelerator, and TIPA is typically used as a grinding agent for cement. In this thesis study TIPA is used in order to increase the ultimate strength of the concrete whose early strengths are increased by Ca(...
Effect of ground perlite incorporation on the performance of blended cements Erdem, T. K.; Akgül, Çağla; Tokyay, Mustafa; Erdoğan, Turhan Y. (2007-06-13) Perlite is a volcanic rock that contains relatively high amounts of SiO2 and Al2O3. Due to its proper chemical composition and glassy structure, it can be used as a pozzolanic addition in blended cements. In this study, ground perlite was used as a cement replacement material in blended cements. Several mortar mixes were prepared to investigate the performance of those cements. The results showed that perlite incorporation caused early age strength losses when compared to the control mortars containing only...
Development of a new short-term concrete prism test method (SCPT) to improve predictability for potential alkali reactivity of aggregates Hafçı, Alkan; Turanlı, Lutfullah.; Department of Civil Engineering (2019) Alkali-aggregate reaction (AAR) is a chemical deterioration process which happens in concrete due to the presence of reactive aggregate, sufficient alkalis and moisture. The analysis for the reactivity may be very difficult because AAR has sophisticated and slow progression behaviour. Analysing the aggregates’ structure in detail is primarily necessary before preparation of concrete mixture. Therefore, fast, simple, and reliable tests should be carried out. In the first step of the study, seven pilot new te...
Effect of test methods on the performance of fiber reinforced concrete with different dosages and matrices Hetemoğlu, Yalçın Oğuz; Yaman, İsmail Özgür; Department of Civil Engineering (2018) Through the last few decades, the idea of adding fibers in to concrete has been quite improved, considering the significant contribution of fibers to the mechanical properties of concrete such as tensile strength, energy absorption capacity and ductility. As a result of many intensive research Fiber Reinforced Concrete (FRC) has become a high-tech material that ensures great performance yet needs efficient design and application. However, the lack of a universally accepted approach and standardized test met...

Citation Formats

O. Musaoğlu, “Effect of reinforcement and pre-stressing force oın ASR expansion,” M.S. - Master of Science, Middle East Technical University, 2012.