Shrinkage of Full-Scale Girders Cast with Self-Consolidating Concrete

2010 ◽  
Vol 129-131 ◽  
pp. 381-385
Author(s):  
Jian Long Wu ◽  
Kamal Henri Khayat ◽  
Feng Xing
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Critical Factor ◽  
Drying Shrinkage ◽  
Cementitious Materials ◽  
Full Scale ◽  
Self Consolidating Concrete ◽  
Binder Type ◽  
Length Changes

Shrinkage can be critical factor for the design of structural members due to the length changes by the time-dependent deformation. In this investigation, two self-consolidating concrete (SCC) and two high-performance concrete (HPC) mixtures with target 56-day compressive strengths of 55 and 69 MPa and having 18-hour release strengths of 34.5 MPa and 43 MPa, respectively, were used to cast four full-scale AASHTO-Type II girders measuring 9.44-m in length. For each strength level, the SCC and HPC mixtures were proportioned with the same water-to-cementitious materials ratio (w/cm) and binder type. The high-range water-reducing admixture (HRWRA) dosage was adjusted to obtain a slump flow of 680 ± 20 mm for the SCC mixtures and a slump of 160 ± 20 mm for the HPC mixtures. The constructability and shrinkage of full-scale girders cast with SCC and HPC mixtures used in precast prestressed girders were investigated and compared. Results of tests on full-scale girders indicated that, SCC placement was successfully carried out by casting the concrete from location at the midspan of the 9.44-m long girders. Both HPC and SCC mixtures developed similar autogenous shrinkage for the mixtures made with the similar w/cm; the two SCC mixtures developed about 20% greater drying shrinkage than the comparable HPC mixtures after 112 days of drying.

Research Progress on Early Autogenous Shrinkage of Cement-Based Cementitious Materials

2013 ◽  
Vol 634-638 ◽  
pp. 2738-2741
Author(s):  
Wei Huang ◽  
Tao Zhang ◽  
Yun Yun Xu
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Research Work ◽  
Autogenous Shrinkage ◽  
Cementitious Materials ◽  
Mineral Admixtures ◽  
Research Progress ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Improvement Measures

Concrete autogenous shrinkage phenomenon would adversely affect the mechanical properties and durability of concrete, this phenomenon is important. Autogenous shrinkage problem of low water-cement ratio of the with high mineral admixtures, cement-based cementitious materials was introduced. The main reason for high-performance concrete early cracking being autogenous shrinkage was pointed out. Based on the home and abroad research status of low water cement ratio of the cement paste and concrete autogenous shrinkage, especially for early autogenous shrinkage phenomenon, the mechanism of autogenous shrinkage and the measure method is presented, and the improvement measures and the possible problems the need for further research work is presented.

scholarly journals Experimental Study of Blended Binders with Metakaolin

2021 ◽  
Vol 13 (19) ◽  
pp. 10548
Author(s):  
Christian Cremona ◽  
Stéphanie Vildaer ◽  
Maxim Cadillac
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Rheological Behaviour ◽  
Mineralogical Composition ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Hardened Concrete ◽  
Flash Calcination ◽  
Creep Measurements

Three metakaolins are evaluated for use as supplementary cementitious materials in cement-based systems. The metakaolins vary in mineralogical composition and in fabrication (traditional and flash calcination), but are quite similar in their surface area (16–19 m2/g), but are quite similar in mineralogical composition. Performance of metakaolin mixtures will be compared to two control mixtures (standard concrete for foundation C40/50 and high performance concrete C60/75). In this study, the properties of fresh concrete and the mechanical and durability properties of hardened concrete will be examined. The rheological behaviour are aimed to determine the effect of metakaolin on mixture workability. Compressive, tensile and flexural strength and elastic modulus will be measured at various concrete ages. The influence of metakaolin on durability is assessed through rapid chloride migration and carbonation measurements. For high performance concrete mixtures, drying and autogenous shrinkage will be monitored and creep measurements are performed and compared.

Shrinkage Properties of Cement-Silica Fume Blended Pastes in Early Age

2017 ◽  
Vol 726 ◽  
pp. 521-526
Author(s):  
Di Zou ◽  
Lian Zhen Xiao ◽  
Wen Chong Shi
Keyword(s):  
Silica Fume ◽  
Rapid Growth ◽  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Early Age ◽  
Shrinkage Ratio ◽  
Study Results ◽  
Expansion Period

The cement-silica fume blended pastes were prepared with different silica fume (SF) dosages of 0%, 5%, 10%, and 15% at different water-binder ratios (W/B) of 0.4 and 0.5. The autogenous shrinkage (AS) and the drying shrinkage (DS) of the paste samples in the hydration period of 7d (168 hours) were measured by a new measurement technique to explore the influence of W/B and silica fume incorporation on the shrinkage in early age. The study results can provide reference for high performance concrete mix design.It is found that ether the AS or the DS of the paste samples shows a similar pattern, and the AS development with hydration time appeared a temporary expansion period after a rapid growth, especially in the samples at a higher W/B or with a lower SF content. However, the DS development did not occur obvious expansion period.Three development trends were obtained for the factors of W/B and SF content. 1) the AS and DS of the pastes mainly occurred in early ages. The lower W/B, the shorter the rapid growth periods, and the higher the shrinkage ratio of 1d to 7d. For the pastes with W/B of 0.4, the AS grew rapidly in 1d and the DS grew rapidly in the first 10h, and the AS value in 1d reached to 63.6% of 7d, and the DS value reached to 62.1% of 7d in the paste with SF of 10%. For the pastes with W/B of 0.5, the rapid growth periods of the AS and DS respectively extended to 30~33h and 12h, and the AS value in 1d reached to 60.0% of 7d, and the DS value reached to 57.2% of 7d in the paste with SF of 10%. 2) The lower W/B, the higher the shrinkage ratio of the AS to the DS. When the SF dosage is 10%, the ratio of the AS value to the DS value of 7d is 21.66%~21.15% for W/B of 0.4, and only 6.06%~5.78% for the W/B of 0.5. 3) the higher SF content results in the higher AS in cement-SF blended pastes. For the pastes with W/B of 0.4, the ratio of the AS to the DS increased from 6.98% to 30.16% with the increase of content of SF from 5% to 15% in 1d, from 15.1% to 28.19% in 3d, from 16.78% to 26.16% in 7d.

Influence of CaO-Based Expansive Agent on the Deformation Behavior of High Performance Concrete

2013 ◽  
Vol 438-439 ◽  
pp. 113-116
Author(s):  
Shou Zhi Zhang ◽  
Qian Tian ◽  
An Qun Lu
Keyword(s):  
Deformation Behavior ◽  
High Performance ◽  
High Performance Concrete ◽  
Control Volume ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Volume Stability ◽  
Expansive Agent ◽  
Effective Expansion ◽  
New Type

In order to improve the volume stability of high performance concrete, the effects of deformation behavior of high performance concrete containing CaO-based expansive agent were investigated. Concrete samples prepared without or with CaO-based expansive agent were compared through expansion under water curing at 20°C, drying shrinkage and autogenous shrinkage measurements. According to the experimental and analytical results, the new type expansive agent can control volume stability for high performance concrete. The addition of 10% CaO-based expansive agent not only built effective expansion in high performance concrete whatever under saturated condition or under sealed condition, but also substantially reduced its drying shrinkage.

Chemical Shrinkage of Pastes Made with Shrinkage Reducing Admixtures

2011 ◽  
Vol 466 ◽  
pp. 105-113 ◽  
Author(s):  
António Bettencourt Ribeiro ◽  
Vasco Medina ◽  
Augusto Gomes ◽  
Arlindo Gonçalves
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Chemical Shrinkage ◽  
Cement Pastes ◽  
Degree Of Hydration ◽  
Shrinkage Cracks ◽  
Large Application ◽  
Shrinkage Reducing Admixtures

Shrinkage Reducing Admixtures (SRA) are being used more often in concrete structures in order to better control shrinkage cracks. High-performance concrete, nowadays with large application, has more proneness to crack at very early age due to the lower W/C. In this type of concrete, autogenous shrinkage is usually more important than drying shrinkage. Autogenous shrinkage is due to the volume decrease inherent to binder hydration reactions. The rate of these reactions is influenced not only by the type of binder but also by the presence of chemical admixtures. It is recognized that SRA delay the hydration, being a secondary effect of this type of admixtures. In this work changes on the degree of hydration of cement pastes with SRA and different binders are presented, using the chemical shrinkage test.

Prediction on Autogenous Shrinkage of Self-Consolidating Concrete

2010 ◽  
Vol 150-151 ◽  
pp. 288-292 ◽  
Author(s):  
Wu Jian Long ◽  
Kamal Henri Khayat ◽  
Feng Xing
Keyword(s):  
High Performance ◽  
Prediction Models ◽  
Autogenous Shrinkage ◽  
Volume Ratio ◽  
Experimental Program ◽  
High Quality ◽  
Self Consolidating Concrete ◽  
Slump Flow ◽  
Binder Type ◽  
Class F Fly Ash

Proper estimate of autogenous shrinkage of self-consolidating concrete (SCC) can provide engineers with the information necessary for producing high quality products manufactured with SCC. An experimental program was undertaken to evaluate autogenous shrinkage of precast, prestressed SCC. Sixteen SCC with slump flow of 680 ± 20 mm were evaluated. These mixtures were made with 440 to 500 kg/m3 of binder, Type MS cement or HE cement and 20% Class F fly ash, 0.34 to 0.40 w/cm, viscosity-modifying admixture content of 0 to 100 mL/100 kg of binder, and 0.46 to 0.54 sand-to-total aggregate volume ratio. Two high-performance concretes (HPC) with 0.34 and 0.38 w/cm and slump of 150 mm were also investigated. HPC developed similar autogenous shrinkage at 56 days compared to SCC made of a given binder type. Shrinkage was compared to prediction models proposed by Tawaza and Miyazawa 1997, Jonasson and Hedlund 2000, and CEB-FIP 1999. The Tazawa and Miyazawa model was modified to provide adequate prediction of autogenous shrinkage for precast, prestressed SCC.

Glass frit for concrete structures: a new, alternative cementitious material

2007 ◽  
Vol 34 (7) ◽  
pp. 793-802 ◽  
Author(s):  
Said Laldji ◽  
Arezki Tagnit-Hamou
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Drying Shrinkage ◽  
Chloride Ion ◽  
Glass Frit ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Supplementary Cementitious Materials ◽  
Partial Replacement ◽  
Concrete Durability

With today's requirements for high-performance concrete, mix proportions containing cementitious materials as partial replacement of, or in addition to, Portland cement, are being used more frequently. The most commonly used cementitious materials nowadays are fly ash, silica fume, and ground, granulated blast-furnace slag. However, alternative supplementary cementitious materials can successfully be used as long as they meet the acceptance criteria stated in various specifications. This paper provides data on properties of structural concrete containing glass frit. The performance of this type of concrete is highlighted by its rheological and mechanical behaviour, as well as its durability. Later-age compressive, splitting tensile, and flexural strengths are well above estimated values, and in many cases, are higher than those obtained with the control concrete. Durability aspects and characteristics expressed by drying shrinkage, surface scaling, and chloride-ion permeability have shown that concrete incorporating glass frit has a very good potential for long-term resistance.Key words: glass frit, cementitious material, workability, mechanical properties, durability.

scholarly journals Evaluation of the Thermal and Shrinkage Stresses in Restrained High-Performance Concrete

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3680 ◽  
Author(s):  
Yang Yang ◽  
Linhao Ma ◽  
Jie Huang ◽  
Chunping Gu ◽  
Zhenjian Xu ◽  
...  
Keyword(s):  
Thermal Stress ◽  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Shrinkage Stress ◽  
Early Age ◽  
Volume Deformation ◽  
Curing Conditions ◽  
Drying Shrinkage Stress

The early age volume deformation is the main course for the cracking of high-performance concrete (HPC). Hence, the shrinkage behavior and the restrained stress development of HPC under different restraints and curing conditions were experimentally studied in this paper. The method to separate the stress components in the total restraint stress was proposed. The total restrained stress was separated into autogenous shrinkage stress, drying shrinkage stress and thermal stress. The results showed that the developments of the free shrinkage (autogenous shrinkage and drying shrinkage) and the restrained stress were accelerated when the drying began; but the age when the drying began did not significantly influence the long-term shrinkage and restrained stress of HPC; the autogenous shrinkage stress continuously contributed to the development of the total restrained stress in HPC; the drying shrinkage stress developed very rapidly soon after the drying began; and the thermal stress was generated when the temperature dropped. The thermal stress was predominant at the early age, but the contributions of the three stresses to the total restrained stress were almost the same at the age of 56 d in this study.

Internal Curing in High Performance Concrete: Effect of Lightweight Aggregate on Shrinkage and Salt Frost Durability

2014 ◽  
Vol 629-630 ◽  
pp. 201-206
Author(s):  
Zhi Chao Liu ◽  
Will Hansen
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Lightweight Aggregate ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Fine Aggregate ◽  
Replacement Level ◽  
Natural Sand ◽  
Frost Durability

High performance concrete (HPC) consisting of low water-binder (w/b) ratio and supplementary cementitious materials (SCM) is more prone to shrinkage cracking if subjected to external deformation restraint. The effectiveness of using lightweight fine aggregate (LWA) for autogenous shrinkage reduction is being studied along with implications on salt frost durability. HPC consisting of 0.33 w/b ratio and cementitious replacement level up to 50% by slag cement and natural sand replacement level by LWA of up to 50% is investigated. Results indicate that these concretes exhibit excellent salt frost resistance provided the HPC is sufficiently air entrained. The mitigation of autogenous shrinkage by LWA is analyzed by comparing the spacing of LWA particles in cement paste and the flow distance of retained moisture in LWA to the adjacent paste.

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