Dissertation > Excellent graduate degree dissertation topics show

Research on Damage Effect and Control Measures of Fiber Reinforced Concrete under Synergy of ASR and Freeze-Thaw Cycle

Author: MaHongNa
Tutor: LouZongKe
School: Northwest University of Science and Technology
Course: Water Resources and Hydropower Engineering
Keywords: Alkali - silica reaction Freeze-thaw cycles Fiber reinforced concrete Combined injury Expansion rate Relative dynamic elastic modulus
CLC: TU528.572
Type: Master's thesis
Year: 2010
Downloads: 80
Quote: 0
Read: Download Dissertation

Abstract


The factors affecting the durability of concrete is complex, and the combined effect of the factors often promote each other, leading to a rapid decline in the durability of concrete. Alkali aggregate reaction and freeze-thaw cycles are two important factors that affect the durability of concrete. At present, the research on the single factor of the durability of concrete damage has been relatively mature and perfect, but on ASR and freeze-thaw cycle synergy mechanism is still not an exact and rational argument. Fiber reinforced concrete based on alkali-silica reaction, freeze-thaw cycle single role effect on the durability of concrete expansion rate, relative move mode two indicators as the damage variable studied in detail in the alkali-silica reaction and freeze-thaw circulation synergistic damaging effects of composite damage effects, and three-factor quadratic regression orthogonal design test methods, measures seeking to suppress the damage and the best combination of the factors for this composite damage. ASR and freeze-thaw cycle is difficult at the same time, the test arrangement a combination of two damage way: First, the first occurrence of ASR and then freezing and thawing; Second, first freezing and thawing and then ASR. Different analysis and a comparison between single action effects and synergy effects. The main conclusions are as follows: (1) For the freeze-thaw cycle occurs first ASR: specimen in the ASR will promote pre occurred late freeze-thaw damage, the greater the degree of response of early ASR (that the higher alkali content), late the greater the freeze-thaw damage expansion coefficient, the more severe cracking, the worse the frost resistance, the smaller the corresponding relative dynamic modulus; alkali content of 1.5% of the end of the specimen test when the expansion ratio and the relative dynamic modulus of 1.265%, respectively, and 62%. (2) For the first occurrence of freeze-thaw damage of ASR: specimen in early by the freezing and thawing cycles, will also promote the latter part of the ASR damage, accelerated injury; early freeze-thaw cycles of the more serious injury, caused by the late ASR injury more serious; the specimen by freezing and thawing cycles, further by ASR injury regularity and a single ASR damage similar similar more serious ASR effect. Early freezing and thawing cycles and no change in the late ASR reaction regularity; freeze-thaw cycles of the concrete internal micro-damage, the change in the microscopic structure of the concrete, and this process alkali enrichment exacerbate ASR damage. (3) specimen in ASR and freeze-thaw cycles the joint action of the two types of destructive elements reflect the deterioration of the value of greater than a single role, and even more than of both single role in the deterioration of indicators. That collaborative destructive effect of ASR and freeze-thaw cycle, the performance of a super-additive effect. (4) by the ternary quadratic regression orthogonal design, research, fly ash, polypropylene fibers, air entraining agent under the the ASR-freeze-thaw collaborative damaging effects of fiber reinforced concrete inhibitory. After analysis derived in the test dosage range, when fly ash take 33.53%, polypropylene dosage take 1.25kg/m3 air-entraining agent mixing 0.0335% inhibitory effect. In addition, the analysis by a single factor effect seen little effect on the expansion rate and the relative role of the dynamic elastic modulus polypropylene fiber.

Related Dissertations

  1. Static Experimental Study on the Layered Steel Fiber Reinforced Concrete Beams after Corrosion,TU375.1
  2. Research on Characteristics of Internal and External Damage of Concrete in Freeze-Thaw Environment,TU528.1
  3. Experimental Study on the Compression Sensitivity of Carbon Fiber Reinforced Concrete under Static and Dynamic Loading,TU528.572
  4. Research for Polypropylene Fiber Concrete Applied in Large-area Ground Engineering,TU528.572
  5. The Production and Emissions of Ammonia and Phosphine from Antarctic Typical Sea Animal Excreta,X142
  6. Bond Durability between FRP and Concrete,TU528.572
  7. Experimental Study on Anti-frozen Durability of Concrete in Saline Soil Region,TU528
  8. Bridge Reinforcement Technology Applied Research,U445.72
  9. Experimental Study of Single Pile Frost Heaving Cycle in Permafrost,TU473.1
  10. The Studies on Friction Characteristics of Slope Protection Interface in Cold Regions,U417.1
  11. The Experimental Research of Piezoelectricity of Carbon Fibers Concrete under Low Temperatures,TU528.572
  12. Experimental Study on Durability of Concrete Specimens Strengthened by BFRP Sheets,TU375
  13. Behavior of Concrete Members Strengthened with Basalt Fiber Reinforced Plastic Sheets under Freeze-Thaw Environment,TU375.1
  14. Mechanism and Kinetics Study on Low Temperature Deacetylation and Pyrolysis in Process of Preparing Natural Water-Soluble Chitosan Using Freezing-Thawing Cyclic Treatment,O636.1
  15. Finite Element Analysis of Steel Fiber Reinforced Concrete Continue Deep Beam,TU375.1
  16. New EGSB Processing High Potency Waste Water Potency and Mechanism Research,X703
  17. Study on Frequent Freeze-thaw Cycle Response of Asphalt Mixture in Permafrost Areas,U414
  18. The Research of the Effect of One-way Load、Freezing-Thawing Cyclcs and Curing Age on Chloride Permeability of Concrete,TU528
  19. Experimental Research on Impact Resistance of Fibre Reinforced Concrete,TU528.572
  20. Experimental Study on the Strength of Concrete under Uniaxial Tensile Load after Freeze-thaw Cycles,TU528
  21. Concrete brick walls Experimental study on seismic behavior,TU362

CLC: > Industrial Technology > Building Science > Building Materials > Non-metallic materials > Concrete and concrete products > Reinforced Concrete > Fiber Reinforced Concrete
© 2012 www.DissertationTopic.Net  Mobile