Effect of watercement ratio and curing temperature on. It is most prominent in high strength, or high performance concrete where the watertocement ratio is under approximately 0. An internal inquiry committee at the science alert has determined that an article entitled autogenous shrinkage of high performance concrete with a mold of lowdensity flexible corrugated pipe published in information technology journal volume 12 number 10, 19581965, 20 contains substantial sections of text that have been taken verbatim from the following article without clear and. Effect of nanosilica on chemical and volume shrinkage of. A possibility of reducing autogenous shrinkage by recycled aggregate which is much more absorbable than normal aggregate is investigated. Autogenous shrinkage of recycledaggregate concrete rac is important for design of concrete structures with recycled aggregate, however, there are f. Autogenous shrinkage of hpc and ways to mitigate it. Pdf a trial of reducing autogenous shrinkage by recycled. Autogenous shrinkage is a major concern in early age cracking of high performance concrete hpc. Such concrete demonstrates significant autogenous shrinkage, which should, however, be limited in the early stages of its development in order to prevent the occurrence of cracks andor drop in the loadcarrying capacity of concrete.
Shrinkage strains need to be investigated as they can. Autogenous shrinkage increased with increasing c 3 a content of. Unit processes of shrinkage behavior based on dynamical analysis of cement paste in different maturity by e. An abstract of the thesis of oregon state university. Use features like bookmarks, note taking and highlighting while reading autogenous shrinkage of concrete. Report on factors affecting shrinkage and creep of. The total and autogenous shrinkages of veslmc were not affected or only slightly affected. Aitcin 18 effect of constituents and curing condition on 269 autogenous shrinkage of concrete e. Prediction of autogenous shrinkage of concretes by support vector machine.
Volume change due to water movement and losses within the concrete are referred to as chemical and autogenous shrinkage and drying and plastic shrinkage are due to water exchange with the surrounding environment. A large amount of autogenous shrinkage was observed in cement paste and concrete with low water to binder ratio. Mesocosm study on characteristic of autogenous shrinkage. For concrete with watercement ratios wc less than 0. Tazawa e, miyazawa s 1999 effect of constituents and curing condition on autogenous shrinkage of concrete. Autogenous shrinkage is a major concern in early age cracking of high performance concrete. Properties and testing of concrete containing fibres other than steel. Cracking increases the probability of ingress of aggressive substances into the concrete, jeopardizing the durability of the material.
Therefore, as of hpc is an important part constituting the total deformation of hpc at early age. Therefore, the aim of this research was to investigate the effect of a combination of expansive admixture ea and shrinkage reducing admixture sa on the autogenous shrinkage of highperformance concrete. Autogenous shrinkage contributes significantly to concrete cracking when the watercement wc ratio is less than 0. The three factors most significantly contributing to the autogenous shrinkage were identified as the concrete s chemical shrinkage, amount of bleeding, and time of. Plastic and drying shrinkage in concrete containing collated fibrillated polypropylene fibres. In this context, cement means total cementitious material, i. Experimental method and prediction model for autogenous. The effect law and mechanism of limestone powder on autogenous shrinkage of concrete was studied. Autogenous shrinkage and expansion related to compressive strength and concrete composition elica marusic, nina stirmer journal of advanced concrete technology,volume, pp. In their studies, a rather unsystematic influence of the curing temperature on the autogenous deformation was found.
The acceleration of hydration process promotes autogenous shrinkage of concrete in the first 10 days. Effect of the key mixture parameters on shrinkage of. Analysis of autogenous and drying shrinkage of concrete. Chemical shrinkage and autogenous deformation of cac binders were tested in a. However, this type of concrete is highly susceptible to the deleterious effects of both autogenous ad ndrying shrinkage. Therefore, the purpose of this study was to quantify and analyse the effect of autogenous shrinkage on the mass transport properties of concrete using three transport tests. When a mitigation strategy relies on the use of chemical admixtures, compatibility with other chemical admixtures is required.
This may be due to the fact that nanosilica has high pozzolanic activity in the early stage. Low watertobinder ratio and incorporation of supplementary cementitious materials scms can. The use of concrete with a somewhat higher wc ratio can mitigate this problem. Autogenousshrinkage model for concrete with coarse and. The paper focuses on the effect of temperature, and discusses how to separate thermal dilation and autogenous deformation with the view to describe. The results indicate that limestone powder accelerates autogenous shrinkage speed of concrete on which effect of fineness is little, and limestone powder reduces autogenous shrinkage which decreases with the increase of fineness. Autogenous shrinkage is usually small for many normal compressive strength concretes and can usually be neglected. Types of shrinkages in concrete and its preventions. Tazawa and miyazawa have reported that, at very low water to binder ratio around 0. Interaction between thermal dilation and autogenous. Data logger with an interface for up to 5 rings aatm the procedure can be used to determine the effects of variations in the proportions and material properties of mortar or concrete on cracking due to both drying shrinkage and deformations caused by autogenous shrinkage and heat of hydration. The paper concerns the driving forces to stress generation and cracking in high performance concrete,i. Autogenous shrinkage is an important pehenomenon in concrete with a watercement ratio less than about 0. Autogenous and drying shrinkage of fibre reinforced high.
Highperformance concrete hpc is widely used in construction according to great mechanical properties, but it has a high risk of shrinkage cracking due to autogenous shrinkage stress. The higher autogenous shrinkage of concrete containing bs may be due to the greater chemical shrinkage than that of the concrete with pure portland cement. Pdf autogenous shrinkage of high performance concrete. In this paper, a svm model for the autogenous shrinkage of concrete mixtures was proposed. Sellevold 17 autogenous shrinkage measurement 257 p. Autogenous shrinkage of concrete tazawa, eiichi on. Autogenous shrinkage is a volume change resulting when there is no moisture transfer to the surrounding environment.
Autogenous shrinkage as well as selfinduced stress of. Technical paper improving test methods to measure early age autogenous shrinkage in concrete based on air cooling muhammad nasir amina, jeongsu kimb, tran thanh datc and jinkeun kimd anust institute of civil engineering, school of civil and environmental engineering, national university of science and technology, islamabad, pakistan. Download it once and read it on your kindle device, pc, phones or tablets. The change law of autogenous shrinkage of concrete is. Calcium aluminate cements cacs were also investigated as part of this research project as a rapid repair material for applications, such as high performance concrete bridge decks. Prediction of autogenous shrinkage in concrete from. College of water conservancy and hydropower engineering, hohai university, nanjing, jiangsu 210098, china. Controlling plastic and autogenous shrinkage in high performance concrete structures by an early water curing by p.
Prediction of autogenous shrinkage of concretes by support. So you can easily integrate it into local intranet. City institute, shanghai municipal engineering design general institute, shanghai 200092, china. Synergistic benefits of using expansive and shrinkage.
Autogenous shrinkage of concrete kindle edition by tazawa, eiichi, eiichi tazawa. Influence of binders and admixtures on autogenous shrinkage 179 of high performance concrete. Low watertobinder ratio and incorporation of supplementary cementitious materials can remarkably increase the shrinkage in the matrix, says a study published in. Veslm concrete with a high latex content and low watercement ratio caused autogenous shrinkage.
Autogenous shrinkage strains may cause cracking of brittle cementbased systems. Earlyage autogenous shrinkage of highperformance concrete columns by embedded fiber bragggrating sensor. Topics include test and prediction methods, the science of autogenous shrinkage, strain and stress, and consequent design concerns. Shrinkage cracking can be mitigated either by reducing shrinkage or by increasing the strain capacity of the concrete. Autogenous shrinkage is the uniform reduction of internal moisture due to cement hydration, which is typical of highstrength concrete. The autogenous shrinkage increased as latex content increased. Autogenous shrinkage and expansion related to compressive. Miyazawa discussions 281 part six modeling of autogenous shrinkage 287.
Serviceability performance evaluation of rc flexural. Construction and building materials, volume 149, 15 september 2017, pages 6275. Effects of cement type, water to binder ratio and volume concentration of aggregate on autogenous shrinkage of cement based materials were experimentally investigated. Types of shrinkages in concrete and its preventions shrinkage is an inherent property of concrete. Topics include test and prediction methods, the science of autogenous shrinkage, strain and stress, and. Technical paper improving test methods to measure early. Effect of mixture composition and size effect on shrinkage of 161 high strength concrete k.
Thus, the greater chemical shrinkage led to faster and greater selfdesiccation, and results in larger autogenous shrinkage. Autogenous shrinkage an overview sciencedirect topics. Chemical shrinkage is like a molecularlevel volume change, and creates the underlying driving force for the occurrence of autogenous shrinkage that is the macroscopic bulk deformation of a closed, isothermal, cementitious material system not subjected to external forces. Thermal and autogenous shrinkages of very early strength. The shrinkage in concrete can be defined as the volume changes observed in concrete due to the loss of moisture at different stages due to different reasons. Material parameters influencing the magnitude of the early age autogenous shrinkage were studied, such as the use of superplasticizer and different cement types. Effect of drying conditions on autogenous shrinkage in. The study discusses the mechanism of autogenous shrinkage.
Reduction of the early autogenous shrinkage of high. Study on shrinkage of concrete with slag composite 155 admixture j. The influence of isothermal curing temperature on autogenous shrinkage is quite complex. Influence of autogenous shrinkage on mass transport. The risk of autogenous shrinkage increases with decrease in the water to binder ratio and with increase or decrease of the amount of the mineral admixtures depending on their. Effect of limestone powder on autogenous shrinkage of concrete. The results of a laboratory investigation on the early autogenous shrinkage of high strength concrete, and the possibilities of its reduction, are presented. Read effect of fly ash on autogenous shrinkage, cement and concrete research on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Autogenous shrinkage of concrete, tazawa, eiichi, eiichi. Tazawa and miyazawas tests 47 showed that adding silica fume to the concrete mix increases the autogenous shrinkage. Autogenous shrinkage of concrete 1st edition eiichi. Mesocosm study on characteristic of autogenous shrinkage for concrete based on hydration degree. Chemical shrinkage and autogenous shrinkage of hydrating cement paste. Read experimental method and prediction model for autogenous shrinkage of high performance concrete, construction and building materials on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.