scholarly journals DEVELOPMENT AND APPLICATION OF NON DRYING-SHRINKAGE TYPE CONCRETE USING HYBRID ADMIXTURE AND EXPANSIVE ADDITIVE

2021 ◽  
Vol 27 (65) ◽  
pp. 30-35
Author(s):  
Kazumasa INOUE ◽  
Daisuke HONMA ◽  
Akiko OGAWA ◽  
Toshiyuki SATO ◽  
Takashi IWASHIMIZU ◽  
...  
Keyword(s):  
Drying Shrinkage ◽  
Expansive Additive

Evaluation of shrinkage and cracking in concrete of ring test by acoustic emission method

2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540033
Author(s):  
Takeshi Watanabe ◽  
Chikanori Hashimoto
Keyword(s):  
Acoustic Emission ◽  
Portland Cement ◽  
Drying Shrinkage ◽  
Length Change ◽  
Ring Test ◽  
Emission Method ◽  
Expansive Additive ◽  
Free Body ◽  
Lime Stone ◽  
Methods Of Measurement

Drying shrinkage of concrete is one of the typical problems related to reduce durability and defilation of concrete structures. Lime stone, expansive additive and low-heat Portland cement are used to reduce drying shrinkage in Japan. Drying shrinkage is commonly evaluated by methods of measurement for length change of mortar and concrete. In these methods, there is detected strain due to drying shrinkage of free body, although visible cracking does not occur. In this study, the ring test was employed to detect strain and age cracking of concrete. The acoustic emission (AE) method was adopted to detect micro cracking due to shrinkage. It was recognized that in concrete using lime stone, expansive additive and low-heat Portland cement are effective to decrease drying shrinkage and visible cracking. Micro cracking due to shrinkage of this concrete was detected and evaluated by the AE method.

scholarly journals Influence of expansive additive on formation of fresh polymer modified pastes

2018 ◽  
Vol 239 ◽  
pp. 01023
Author(s):  
Oksana Larsen ◽  
Marsel Nurtdinov ◽  
Viktoria Shvetsova ◽  
Ekaterina Fomina
Keyword(s):  
Structure Formation ◽  
Drying Shrinkage ◽  
Initial Mixture ◽  
Heat Evolution ◽  
Water Soluble ◽  
Strength Development ◽  
Cement Ratio ◽  
Expansive Additive ◽  
Evolution Behavior ◽  
Polymer Dispersions

Chemical admixtures are widely used in cement-based mixtures to reduce water demand, increase working time or accelerate strength development. The application of water-soluble polymers in building industry is increasing. The performance of cement mortars and concretes can be improved by the modification of their structure with additives of polymers. The use of polymers in cement-based compositions can decrease the intensity of hydration kinetic and increase the shrinkage deformation. Hardening of polymer-modified cement-based mixtures is associated with drying shrinkage which can significantly decrease crack resistance of cement concretes, especially in the case of polymer dispersions. The influence of polymer admixture with expansive additive on formation of cement-based pastes was investigated. Structure formation of fresh polymer modified cementitious mixtures with expansive additive was experimentally investigated by heat evolution behavior. Structure formation as a function of time and depends from initial mixture design properties such as water-cement ratio, polymer-cement ratio and content of expansive additive.

scholarly journals Drying shrinkage, strength and microstructure of alkali-activated high-calcium fly ash using FGD-gypsum and dolomite as expansive additive

2020 ◽  
Vol 114 ◽  
pp. 103760 ◽  
Author(s):  
Sakonwan Hanjitsuwan ◽  
Borwonrak Injorhor ◽  
Tanakorn Phoo-ngernkham ◽  
Nattapong Damrongwiriyanupap ◽  
Long-Yuan Li ◽  
...  
Keyword(s):  
Fly Ash ◽  
Drying Shrinkage ◽  
Fgd Gypsum ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Expansive Additive ◽  
Alkali Activated

scholarly journals Experimental Study on the Shrinkage Behavior and Mechanical Properties of AAM Mortar Mixed with CSA Expansive Additive

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3312 ◽  
Author(s):  
Sung Choi ◽  
Gum-Sung Ryu ◽  
Kyeong-Taek Koh ◽  
Gi-Hong An ◽  
Hyeong-Yeol Kim
Keyword(s):  
Modulus Of Elasticity ◽  
Compensation Effect ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Shrinkage Stress ◽  
Calcium Sulfoaluminate ◽  
Total Shrinkage ◽  
Expansive Additive ◽  
Shrinkage Compensation

In this study, a calcium sulfoaluminate-based expansive additive (0%, 2.5%, 5.0%, and 7.5% by the mass of the binder) was added to compensate for the shrinkage of alkali-activated material (AAM) mortar. Modulus of elasticity curves based on the ACI 209 model were derived for the AAM mortar mixed with the additive by measuring the compressive strength and modulus of elasticity. Moreover, autogenous shrinkage and total shrinkage were measured for 150 days, and drying shrinkage was calculated by excluding autogenous shrinkage from total shrinkage. For the autogenous and drying shrinkage of AAM mortar, shrinkage curves by age were obtained by deriving material constants using the exponential function model. Finally, shrinkage stress was calculated using the modulus of elasticity of the AAM mortar and the curves obtained using the shrinkage model. The results showed that the calcium sulfoaluminate-based expansive additive had an excellent compensation effect on the drying shrinkage of AAM mortar, but the effect was observed only at early ages when the modulus of elasticity was low. From a long-term perspective, the shrinkage compensation effect was low when the modulus of elasticity was high, and thus, shrinkage stress could not be reduced.

scholarly journals STUDY OF EFFICIENCY OF NEWLY DEVELOPED SUPER LOW DRYING-SHRINKAGE CONCRETE USING HYBRID ADMIXTURE AND EXPANSIVE ADDITIVE

2016 ◽  
Vol 22 (51) ◽  
pp. 409-414
Author(s):  
Kazumasa INOUE ◽  
Daisuke HONMA ◽  
Takashi IWASHIMIZU ◽  
Toshiyuki SATO ◽  
Kazuhide SAITO ◽  
...  
Keyword(s):  
Drying Shrinkage ◽  
Expansive Additive

Analysis of Drying Shrinkage of the Concrete Using Calcium Sulfa Aluminate(CSA) Based Expansive Additive

2011 ◽  
Vol 121-126 ◽  
pp. 2445-2450
Author(s):  
Chun Jin Park ◽  
Kyung Taek Koh ◽  
Min Cheol Han ◽  
Cheon Goo Han
Keyword(s):  
Mechanical Properties ◽  
Drying Shrinkage ◽  
Japan Society ◽  
Expansive Additive ◽  
Interpretation Model ◽  
Civil Engineers

This study purposed to analyze the mechanical properties of concrete using the expansive additive in order to control the drying shrinkage of concrete and to propose a time-depending drying shrinkage interpretation model considering the influence of expansive additive based on Japan Society of Civil Engineers (JSCE) Model, so the summarized results are as follows: According to the results to perform the drying shrinkage interpretation of concrete using the expansive additive through the proposed the intepretation model, it can be known that the interpretation value in every mixture usually assumes the measurement value well and that the model proposed in this study was statically relevant through exaimining its effectiveness. It can be thought to evaluate and anticipate well the drying shrinkage of concrete using the expansive additive on field through this model formula in future.

A novel multi-functional expansive additive for drying shrinkage reduction in mortars

2010 ◽  
pp. 877-881
Author(s):  
P Hamedanimojarrad ◽  
G Adam ◽  
A Ray ◽  
K Vessalas ◽  
P Thomas ◽  
...  
Keyword(s):  
Drying Shrinkage ◽  
Expansive Additive

Modified gach technique vs critical point drying: Shrinkage analysis for SEM

1987 ◽  
Vol 45 ◽  
pp. 954-955
Author(s):  
B. Thompson ◽  
N. Sculov ◽  
R.E. Crang
Keyword(s):  
Critical Point ◽  
Calf Serum ◽  
Drying Shrinkage ◽  
Specimen Preparation ◽  
Cell Shrinkage ◽  
Whole Cells ◽  
Critical Point Drying ◽  
Prepared Material ◽  
Inverted Microscope ◽  
Phosphate Buffered Saline

The use of co-polymerized glutaraldehyde-carbohydrazide (GACH) was proposed for specimen preparation in scanning electron microscopy (SEM) as a means of avoiding dehydration in organic solvents, and to provide dimensionally stable biological specimens through a process of air-drying. It has been assumed that shrinkage of specimens prepared by the GACH technique should be less than that of conventionally-prepared material by critical point drying (CPD). In a previous study, Bell has reported significant shrinkage of whole cells for SEM. This report compares cell shrinkage in GACH and CPD preparations.Fibroblasts from newborn rats were grown on collagen-coated glass cover-slips (with alpha numeric grids etched onto the surface of the coverslips) in Eagle's minimum essential medium + 10% fetal calf serum for 7 d. (3). Using an inverted microscope with phase-contrast optics, micrographs were taken of the cultures in their live state and 1 h. after fixation with 2.5% glutaraldehyde in Dulbecco's phosphate buffered saline (Figs. 1 and 3).

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