Study on Adding Super Absorbent Polymer to Improve the Frost Resistance of Concrete

2014 ◽  
Vol 584-586 ◽  
pp. 960-963 ◽  
Author(s):  
De Zhi Wang ◽  
Yin Yan Zhang ◽  
Yun Fang Meng
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Frost Resistance ◽  
Strength Loss ◽  
Internal Curing ◽  
Super Absorbent Polymer ◽  
Freeze Thaw ◽  
Absorbent Polymer

Internal curing was especially beneficial to improve concrete performance. The super absorbent polymer and fly ash were used in the concrete and the frost resistance of concrete was studied. The result indicated that the super absorbent polymer changed the pore structure, increased the quantity of the pore, decreased the strength loss 5-10% after 250 freeze-thaw cycles and improved the frost resistance of concrete.

scholarly journals Freeze–Thaw Resistance and Air-Void Analysis of Concrete with Recycled Glass–Pozzolan Using X-ray Micro-Tomography

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 154
Author(s):  
Marija Krstic ◽  
Julio F. Davalos ◽  
Emanuele Rossi ◽  
Stefan C. Figueiredo ◽  
Oguzhan Copuroglu
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
The United States ◽  
Adsorption Method ◽  
X Ray ◽  
Freeze Thaw ◽  
Void System ◽  
Spatial Parameters ◽  
Micro Tomography ◽  
Air Void

Recent studies have shown promising potential for using Glass Pozzolan (GP) as an alternative supplementary cementitious material (SCM) due to the scarcity of fly ash and slag in the United States. However, comprehensive studies on the freeze–thaw (FT) resistance and air void system of mixtures containing GP are lacking. Therefore, this study aimed to evaluate GP’s effect on FT resistance and characterize mixtures with different GP contents, both macro- and microscopically. In this study, six concrete mixes were considered: Three mixes with 20%, 30% and 40% GP as cement replacements and two other comparable mixes with 30% fly ash and 40% slag, as well as a mix with 100% Ordinary Portland cement (OPC) as a reference. Concrete samples were prepared, cured and tested according to the ASTM standards for accelerated FT resistance for 1000 cycles and corresponding dynamic modulus of elasticity (Ed). All the samples showed minimal deterioration and scaling and high F/T resistance with a durability factor of over 90%. The relationships among FT resistance parameters, air-pressured method measurements of fresh concretes and air void analysis parameters of hardened concretes were examined in this study. X-ray micro-tomography (micro-CT scan) was used to evaluate micro-cracks development after 1000 freeze–thaw cycles and to determine spatial parameters of air voids in the concretes. Pore structure properties obtained from mercury intrusion porosimetry (MIP) and N2 adsorption method showed refined pore structure for higher cement replacement with GP, indicating more gel formation (C-S-H) which was verified by thermogravimetric analysis (TGA).

Experiment Study on the Durability of Dry-Mixing Self-Compacting Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 493-496 ◽  
Author(s):  
Lan Zong ◽  
Shi Ping Zhang ◽  
Pei Xin Liang
Keyword(s):  
Pore Structure ◽  
Frost Resistance ◽  
Chloride Ions ◽  
Experiment Study ◽  
Self Compacting Concrete ◽  
Freeze Thaw ◽  
Coarse Aggregates ◽  
Carbonation Resistance ◽  
Dry Mixing ◽  
Chloride Ions Diffusion

Durability of dry-mixing self-compacting concrete was evaluated through carbonation testing, freeze-thaw testing and chloride ions diffusion testing. The results indicate that carbonation resistance, frost resistance and chloride ions diffusion of durability of dry-mixing self-compacting concrete are excellent, compared with normally vibrated concrete (NVC). Durability of dry-mixing self-compacting concrete shows a better pore structure. Furthermore, the more the content of coarse aggregates is, the poorer the pore structure becomes.

scholarly journals Effects of Mixing and Curing Temperature on the Strength Development and Pore Structure of Fly Ash Blended Mass Concrete

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Ki-Bong Park ◽  
Takafumi Noguchi
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Pore Structure ◽  
Weather Conditions ◽  
Strength Loss ◽  
Curing Temperature ◽  
Strength Development ◽  
Mass Concrete ◽  
Term Strength

The aim of this work is to know clearly the effects of temperature in response to curing condition, hydration heat, and outside weather conditions on the strength development of high-performance concrete. The concrete walls were designed using three different sizes and three different types of concrete. The experiments were conducted under typical summer and winter weather conditions. Temperature histories at different locations in the walls were recorded and the strength developments of concrete at those locations were measured. The main factors investigated that influence the strength developments of the obtained samples were the bound water contents, the hydration products, and the pore structure. Testing results indicated that the elevated summer temperatures did not affect the early-age strength gain of concrete made using ordinary Portland cement. Strength development was significantly increased at early ages in concrete made using belite-rich Portland cement or with the addition of fly ash. The elevated temperatures resulted in a long-term strength loss in both belite-rich and fly ash containing concrete. The long-term strength loss was caused by a reduction in the degree of hydration and an increase in the total porosity and amount of smaller pores in the material.

scholarly journals A Method for Internal Curing Water Calculation of Concrete with Super Absorbent Polymer

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Shouqi Zhang ◽  
Zhenbao Lu ◽  
Yongxin Li ◽  
Yuan Ang ◽  
Kechao Zhang
Keyword(s):  
Phase Distribution ◽  
Autogenous Shrinkage ◽  
Mineral Admixture ◽  
Internal Curing ◽  
Hardened Concrete ◽  
Hardened Cement ◽  
Cement Pastes ◽  
Super Absorbent Polymer ◽  
Degree Of Hydration ◽  
Absorbent Polymer

The internal curing method is effective in reducing the self-desiccation of concrete, and the amount of internal curing water (IC water) is greatly important to the shrinkage and strength of concrete. A method for calculating IC water of concrete with and without mineral admixture has been developed. The method is derived from Powers’ model for the phase distribution of a hydrating cement paste. To verify the method, a series of autogenous shrinkage and compressive strength of concrete with and without super absorbent polymer (SAP) were evaluated compared with the method proposed previously. To explain the macro performance of hardened concrete, the nonevaporable water content and calcium hydroxide content measurement were utilized to evaluate the degree of hydration of cement pastes. And, mercury intrusion method and image analysis method were used to explore the pore structure in hardened cement pastes and air void characteristics in hardened concrete, respectively. Furthermore, the evolution process was also studied for the relative humidity inside the concrete.

scholarly journals Ilmenite Mud Waste as an Additive for Frost Resistance in Sustainable Concrete

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2904 ◽  
Author(s):  
Filip Chyliński ◽  
Krzysztof Kuczyński
Keyword(s):  
Titanium Dioxide ◽  
Fly Ash ◽  
Frost Resistance ◽  
Building Materials ◽  
Industrial Wastes ◽  
Cement Matrix ◽  
Freeze Thaw ◽  
Sustainable Concrete ◽  
Potential Risks ◽  
Air Void

Sustainable development leads to the production of building materials that are safer for the environment. One of the ways to achieve sustainability in materials is the addition of industrial wastes and by-products, especially to concrete. However, the addition of waste to concrete often decreases its durability and the scope of aggression of the environment in which the concrete is used has to be reduced. Making sustainable concrete, which is also durable in more aggressive environments, is rather difficult. This article presents the results of tests performed on concrete containing ilmenite mud waste from the production of titanium dioxide, which was exposed to frost aggression with and without de-icing salts. The results have shown that a sustainable and frost resistant concrete can be made. After 200 freeze–thaw cycles, the compressive strength of the tested concretes decreased by less than 4%. Concretes were highly resistant for scaling and after 112 freeze–thaw cycles in water with de-icing salt, the scaled mass was less than 0.02 kg/m2. The air void distribution has also been analyzed. The results suited the requirements for frost resistance concrete and were similar to those obtained for a reference concrete with fly ash. The examination of the microstructure using scanning electron microscopy (SEM) has not shown any potential risks that might affect the durability of concrete. Particles of waste were thoroughly combined in the binder and some of its constituents seem to be an active part of the cement matrix. Long-term tests of shrinkage (360 days) have not shown any excessive values that would differ from the reference concrete with fly ash. The presented results have shown that sustainable concrete containing ilmenite mud waste from the production of titanium dioxide might also be resistant to frost aggression.

scholarly journals Efficiency of Sodium Polyacrylate to Improve Durability of Concrete under Adverse Curing Condition

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Tanvir Manzur ◽  
Shohana Iffat ◽  
Munaz Ahmed Noor
Keyword(s):  
Internal Curing ◽  
Curing Agent ◽  
Sodium Polyacrylate ◽  
Curing Process ◽  
Super Absorbent Polymer ◽  
Curing Conditions ◽  
Naturally Occurring ◽  
Additional Water ◽  
Strength And Durability ◽  
Absorbent Polymer

The conventional external curing process requires supply of large amount of water in addition to mixing water as well as strict quality control protocol. However, in a developing country like Bangladesh, many local contractors do not have awareness and required knowledge on importance of curing which often results in weaker concrete with durability issues. Moreover, at times it is difficult to maintain proper external curing process due to nonavailability of water and skilled laborer. Internal curing can be adopted under such scenario since this method is simple and less quality intensive. Usually, naturally occurring porous light weight aggregates (LWA) are used as internal curing agent. However, naturally occurring LWA are not available in many countries like Bangladesh. Under these circumstances, Super Absorbent Polymer (SAP) can be utilized as an alternative internal curing agent. In this study, sodium polyacrylate (SP) as SAP has been used to produce internally cured concrete. Desorption isotherm of SP has been developed to investigate its effectiveness as internal curing agent. Test results showed that internally cured concrete with SP performed better in terms of both strength and durability as compared to control samples when subjected to adverse curing conditions where supply of additional water for external curing was absent.

Effects of Internal Curing by Super Absorbent Polymer on Shrinkage of Concrete

2011 ◽  
Vol 477 ◽  
pp. 200-204 ◽  
Author(s):  
Lu Feng Pang ◽  
Shi Ye Ruan ◽  
Yong Tao Cai
Keyword(s):  
Cement Mortar ◽  
Internal Curing ◽  
Blank Group ◽  
Super Absorbent Polymer ◽  
Absorbent Polymer

This paper focuses on the shrinkage of concrete, influenced by the different mixing amount of super absorbent polymer—SAP and extra-water. The experiment showed that the SAP-cement-mortar shrinkage is reduced greatly by mixing SAP. Extra-water can improve the function of reducing shrinkage of SAP. When the amount is 20, the shrinkage is lest, account for 57% of blank group’s. The SAP has well effect on the cement mortar shrinkage. Besides, we found that the strength of this group account for 89% of blank group. So the proper amount of SAP and extra-water has poorly influence on the strength of concrete.

scholarly journals The Influence of Regional Freeze–Thaw Cycles on Loess Landslides: Analysis of Strength Deterioration of Loess with Changes in Pore Structure

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3047
Author(s):  
Zuyong Li ◽  
Gengshe Yang ◽  
Hui Liu
Keyword(s):  
Pore Structure ◽  
Triaxial Compression ◽  
Strength Loss ◽  
Loess Landslide ◽  
Strength Deterioration ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Loess Landslides ◽  
The Stability

The loess landslide in Gaoling District of Xi’an, Shaanxi in China is closely related to the seasonal freeze–thaw cycle, which is manifested by the destruction of pore structure and strength deterioration of the loess body under freeze–thaw conditions. In order to study the relationship between macro-strength damage and pore structure deterioration of saturated loess under freeze–thaw conditions and its influence on the stability of landslides, this paper explores the effect of freeze–thaw cycles on the strength of saturated undisturbed loess through triaxial compression test, and explores the micro-microstructure changes of saturated undisturbed loess through scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR). This is to analyze the evolution of the pore structure and strength loss evolution of saturated loess during the freeze–thaw process, and to describe the freeze–thaw damage of saturated undisturbed loess through the change of porosity and strength deterioration. Then, the internal correlation expression between the porosity change and the strength degradation is established to realize the verification analysis of the test data based on the correlation model. The research results show that: (1) As the number of freeze–thaw cycles increases, the peak strength loss rate gradually increases, and the strength deterioration of saturated loess becomes more and more obvious. (2) The freeze–thaw cycle will lead to the development of pores and cracks in the sample, accompanied by the generation of new cracks, which will cause the deterioration of the pore structure of the sample as a whole. (3) The response of strength damage and porosity deterioration of saturated undisturbed loess is roughly similar under the freeze–thaw cycle. The change in porosity can be measured to better reflect the strength deterioration of saturated loess. Therefore, the change of pore structure of undisturbed loess under freeze–thaw cycle conditions is tested by field sampling and indoor tests to reflect the phenomenon of strength deterioration, thereby analyzing the stability of loess slopes.

scholarly journals Relationship between Moisture Transportation, Efflorescence and Structure Degradation in Fly Ash/Slag Geopolymer

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5550
Author(s):  
Shuaikang Zhou ◽  
Suhua Zhou ◽  
Jiuchang Zhang ◽  
Xin Tan ◽  
Deng Chen
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Sodium Carbonate ◽  
Strength Loss ◽  
Absorption Capacity ◽  
Curved Surface ◽  
Capillary Absorption ◽  
Structure Degradation

The relationship between moisture transportation and efflorescence in sodium hydroxide- or sodium silicate-activated fly ash/slag geopolymers was investigated. The results show that the efflorescence products are sodium carbonate hydrates, mainly composed of natron, heptahydrate, trona and sodium carbonate. The efflorescence induces compressive strength loss, water absorption increases and pore structure degradation in the geopolymer. When the curved surface of a geopolymer cylinder is covered with plastic film, the moisture transportation drives the free alkalis to the top surface to initiate efflorescence. In comparison, the efflorescence occurring on the curved surface of an uncovered geopolymer cylinder results in a more intensive alkalinity loss. For the uncovered geopolymers prepared with sodium hydroxide activator, efflorescence deposits are formed on the lower half of cylinder. A low capillary absorption capacity developed in the pore structure can only drive the moisture to the middle of cylinder, which is confronted with the drying front. More efflorescence products are formed on the upper half of the uncovered geopolymer cylinder prepared with sodium silicate activator. A relatively higher capillary absorption capacity, developed in the more compact pore structure, transports the moisture from the bottom to the top of cylinder, so no drying line is observed in the cylinder.

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