scholarly journals Effect of Internal Pores Formed by a Superabsorbent Polymer on Durability and Drying Shrinkage of Concrete Specimens

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5199
Author(s):  
Il-Sun Kim ◽  
So-Yeong Choi ◽  
Yoon-Suk Choi ◽  
Eun-Ik Yang
Keyword(s):  
Compressive Strength ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Penetration Depth ◽  
Drying Shrinkage ◽  
Chloride Penetration ◽  
Superabsorbent Polymer ◽  
Concrete Mix ◽  
Air Entrained Concrete

In this study, the effect of internal pores formed by a superabsorbent polymer (SAP) was analyzed by evaluating the compressive strength, chloride penetration depth, drying shrinkage, and pore size distribution of SAP-containing concrete, while securing workability using a water-reducing agent (WRA). The experimental results showed that the amount of WRA necessary increased as the amount of SAP added increased, and that the compressive strength was the highest when the SAP content was 1.5% of the concrete mix. Drying shrinkage tended to decrease as the SAP content increased, and it decreased by approximately 31–41% when the SAP content was 2.0% compared to that of the reference mix. The SAP expanded by approximately three times inside concrete, and it was distributed within the internal pores of air-entrained concrete. The optimal SAP content in concrete mix was 1.5%, and an SAP content of 2.0% or higher adversely affected the workability and compressive strength.

Preparation and Characteristics of Integral Water Repellent Cement-Based Materials

2011 ◽  
Vol 675-677 ◽  
pp. 1189-1192 ◽  
Author(s):  
Peng Zhang ◽  
Tie Jun Zhao ◽  
F.H. Wittmann ◽  
Shao Chun Li
Keyword(s):  
Compressive Strength ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Reduction Rate ◽  
Chloride Penetration ◽  
Water Repellent ◽  
Entire Volume ◽  
Capillary Suction ◽  
Cement Based Materials

Polymers are often applied in concrete for multiple purposes and aims. For instance, surface impregnation of concrete with silanes is a reliable technology to protect cement-based materials from ingress of aggressive solutions into the materials. An alternative method is to add silane emulsion into fresh concrete or mortar to produce integral water repellent materials. In this contribution integral water repellent concrete was prepared by adding 1 %, 2 %, 3 %, 4 % and 6 % of silane emulsion. The influence of silane emulsion on the compressive strength, porosity and pore size distribution, water capillary suction and chloride penetration have been investigated. The results indicate that addition of silane emulsion moderately reduced compressive strength of concrete. With 3 % of silane emulsion the reduction is about 10 %. The addition of silane emulsion hardly has influence on pore size distribution. Silane does not block the capillary pores, but only forms a hydrophobic film on the walls of capillary pores. Addition of silane emulsion reduces water capillary suction significantly. The reduction rate is higher than 89 %. Even the surface of integral water repellent concrete is abraded off 7 mm, the material still demonstrates high water repellency because the entire volume is hydrophobic. In addition, chloride penetration also can be reduced substantially.

Microstructure and Porosity of Metakaolin Blended Cements

1988 ◽  
Vol 136 ◽  
Author(s):  
P. Bredy ◽  
M. Chabannet ◽  
J. Pera
Keyword(s):  
Compressive Strength ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Hydrated Cement ◽  
Cement Pastes ◽  
Blended Cements ◽  
Mercury Intrusion ◽  
Pozzolanic Cement

ABSTRACTFive compositions with 10% to 50% metakaolin for cement substitution were studied. The rate of hydration was studied from the compressive strength after up to 6 months of curing and from the hydrates formed (DTA-XRD). The metakaolin addition considerably reduced portlandite content in the hydrated cement and contributed to the formation of hydrated gehlenite which is not present in OPC paste. The microstructure study (SEM) shows that pozzolanic cement pastes were less crystallized than plain pastes. Mercury intrusion was used to measure porosity of hydrated cement pastes. The porosity with blended cements was higher than that with OPC, except for 10 and 20% metakaolin substitution. Evolution of the pore size distribution was studied: the pozzolanic pastes enhance small diameters.

scholarly journals Embedded NMR Sensor to Monitor Compressive Strength Development and Pore Size Distribution in Hydrating Concrete

Sensors ◽  
2013 ◽  
Vol 13 (12) ◽  
pp. 15985-15999 ◽  
Author(s):  
Floriberto Díaz-Díaz ◽  
Prisciliano de J. Cano-Barrita ◽  
Bruce Balcom ◽  
Sergio Solís-Nájera ◽  
Alfredo Rodríguez
Keyword(s):  
Compressive Strength ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Strength Development ◽  
Compressive Strength Development

scholarly journals EXPERIMENTAL STUDY ON DRYING SHRINKAGE AND PORE SIZE DISTRIBUTION OF AGGREGATE IN KANSAI AREA

2001 ◽  
Vol 66 (549) ◽  
pp. 1-6 ◽  
Author(s):  
Kazuhiko TATEMATSU ◽  
Masanao ARAI ◽  
Takashi IWASHIMIZU ◽  
Yoshimoto KIMURA ◽  
Hideo URANO ◽  
...  
Keyword(s):  
Experimental Study ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Drying Shrinkage

Microstructure and Porosity of Metakaolin Blended Cements

1988 ◽  
Vol 137 ◽  
Author(s):  
P. Bredy ◽  
M. Chabannet ◽  
J. Pera
Keyword(s):  
Compressive Strength ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Hydrated Cement ◽  
Cement Pastes ◽  
Blended Cements ◽  
Mercury Intrusion ◽  
Pozzolanic Cement

AbstractFive compositions with 10% to 50% metakaolin for cement substitution were studied. The rate of hydration was studied from the compressive strength after up to 6 months of curing and from the hydrates formed (DTA-XRD). The metakaolin addition considerably reduced portlandite content in the hydrated cement and contributed to the formation of hydrated gehlenite which is not present in OPC paste. The microstructure study (SEM) shows that pozzolanic cement pastes were less crystallized than plain pastes. Mercury intrusion was used to measure porosity of hydrated cement pastes. The porosity with blended cements was higher than that with OPC, except for 10 and 20% metakaolin substitution. Evolution of the pore size distribution was studied: the pozzolanic pastes enhance small diameters.

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