Creep and shrinkage of high strength and durable concrete containing high volume fly ash | |
| Author | Samrerng Thongton |
| Call Number | AIT Thesis no.ST-07-13 |
| Subject(s) | Concrete--Creep Concrete--Expansion and contraction |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Structural Engineering, School of Engineering and Technololgy |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ST-07-13 |
| Abstract | The main objective of the investigation is to study the influence of using high volume fly ash on the compressive strength at different ages, creep and shrinkage, durability of concrete expressed as chloride permeability. The workability of concrete expressed in term of slump is kept constant by varying the water-to-binder (W/B) ratios. Two types of pozzolanic material are used namely pulverized fly ash and the combination of pulverized fly ash and condensed silica fume. The cementitous material is 350 kg/m3 with W/B from 0.32 to 0.33 and the dosage of superplasticizer which is based on poly-carboxylic ether (PCE) were used 2% of binder for all mixes. Control specimens without using pozzolanic materials of concrete are also cast and tested for comparison. This study was conducted the mix proportions high strength and durable concrete by using replacement of fly ash and condensed silica fume. Test results showed that the compressive strength of concrete is found to decrease as the pulverized fly ash replacement level increases. However, the compressive strength of mixtures containing both pulverized fly ash and condensed silica fume was greater than the mixtures with only fly ash content. The results confirm that high volume fly ash concrete is a promising material for long term strength development. This was due to the fact that early age strength of high volume fly ash concrete was lower as compared to strength of control concrete. The magnitude of creep of concrete increased as the pulverized fly ash replacement level increases. However, the creep of mixtures containing both pulverized fly ash and condensed silica fume was lower than the mixtures with only fly ash content. The relationship for control and high volume fly ash concretes. It is evident that creep of control concrete is lower than that of high volume fly ash concretes at early ages of loading for all stress-strength ratios. The chloride permeability of concrete containing higher pulverized fly ash content decrease as the pulverized fly ash content increases. However, the chloride permeability of mixtures containing both pulverized fly ash and condensed silica fume was lower than the mixtures with only fly ash content. Pulverized fly ash and silica fume can be satisfactorily used as a cement replacement material in order to reduce the chloride permeability and hence increase the durability of concrete. The relationship between compressive strength and creep of concrete containing different percentage replacement of fly ash. It is evident that creep of control concrete is lower than that of high volume fly ash concretes at early ages of loading for all stress-strength ratios. This was due to the fact that early age strength of high volume fly ash concretes was lower as compared to strength of control concrete. The relationship between compressive strength and chloride permeability of concrete containing different percentage replacement of fly ash. It is of interest to note that for fly ash, the compressive strengths at 28 days of concrete were reduced as compared with those of the control mix. The charge passed of high volume fly ash concretes were significantly reduced which means that the durability of concrete is high. However, the use of both pulverized fly ash and condensed silica fume as cement replacement increased strength, reduced creep and improved chloride permeability resistance more than the mixtures with only fly ash content. It could be concluded that the use of combination of 30% pulverized fly ash and 5% condensed silica fume as cement replacement increased strength, reduced creep, and improved chloride permeability resistance. |
| Year | 2007 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. ST-07-13 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Pichai Nimityongskul; |
| Examination Committee(s) | Thanakorn Pheeraphan;Kato, Yoshitaka; |
| Scholarship Donor(s) | RTG Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2007 |