Influence of Aggregates on Cracking Sensitivity of Concrete

2013 ◽  
Vol 368-370 ◽  
pp. 939-944
Author(s):  
Xia Chen ◽  
Yan Shi ◽  
Yu Qiang Lin ◽  
Xiang Li ◽  
Shi Hua Zhou ◽  
...  
Keyword(s):  
Water Absorption ◽  
High Water ◽  
Thermal Impact ◽  
Construction Sites ◽  
Comprehensive Investigation ◽  
High Water Absorption ◽  
Close Relationship ◽  
Under Construction ◽  
Hydropower Stations ◽  
Better Than

Upon large demands from southwest of China where a large number of hydropower stations are schemed or under construction with presence of a variety of aggregates, it is of necessity to launch a comprehensive investigation on influence of aggregates on properties of concrete which was rarely reported before. Four types of aggregates selected from different construction sites were used to conduct tests, and results indicated that water absorption of aggregates exhibited a consistent rising tendency over 180 days and it had close relationship with autogenously shrinkage of concrete which varied in the manner that high water absorption of aggregates produced more obvious shrinkage. With employment of advanced temperature and stress machine, concrete made with diorite and basalt was rated better than limestone and natural granite concrete in crack resistance based on comparison of cracking temperature and thermal impact according to RILEM TC119.

scholarly journals Cellulose Nanofibrils/Xyloglucan Bio-Based Aerogels with Shape Recovery

Gels ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 5
Author(s):  
Samuel Mandin ◽  
Samuel Moreau ◽  
Malika Talantikite ◽  
Bruno Novalès ◽  
Jean-Eudes Maigret ◽  
...  
Keyword(s):  
Water Absorption ◽  
Shape Recovery ◽  
Cellulose Nanofibrils ◽  
High Water ◽  
Absorption Capacity ◽  
Absorption Properties ◽  
High Affinity ◽  
High Water Absorption ◽  
Freezing Procedure ◽  
The Impact

Bio-based aerogels containing cellulose nanofibrils (CNFs) are promising materials due to the inherent physical properties of CNF. The high affinity of cellulose to plant hemicelluloses (xyloglucan, xylan, pectin) is also an opportunity to develop biomaterials with new properties. Here, we prepared aerogels from gelled dispersions of CNFs and xyloglucan (XG) at different ratios by using a freeze-casting procedure in unidirectional (UD) and non-directional (ND) manners. As showed by rheology analysis, CNF and CNF/XG dispersions behave as true gels. We investigated the impact of the freezing procedure and the gel’s composition on the microstructure and the water absorption properties. The introduction of XG greatly affects the microstructure of the aerogel from lamellar to cellular morphology. Bio-based aerogels showed high water absorption capacity with shape recovery after compression. The relation between morphology and aerogel compositions is discussed.

scholarly journals OPTIMUM PERFORMANCE OF STABILIZED EDE LATERITE AS AN ALTERNATIVE CONSTRUCTION MATERIAL

2020 ◽  
Vol 3 (8) ◽  
pp. 1-8
Author(s):  
Adegbenle Bukunmi O
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Construction Material ◽  
High Water ◽  
Good Alternative ◽  
Linear Shrinkage ◽  
Absorption Capacity ◽  
Water Absorption Capacity ◽  
Optimum Performance ◽  
High Water Absorption

Laterite samples from Ede area with particle components of 19.7% clay, 32.8% silt and 47.5% sand was stabilized with combined cement, lime and bitumen and test for Compressive strength, Linear Shrinkage, Permeability and Water Absorption. The stabilizers were mixed with laterite soil in different ratios and percentage. The laterite carried 90% which is constant while the three stabilizers shared the remaining 10% in varying form. After 28 days of curing, laterite stabilizer with 90% of laterite, 8% of cement, 1% lime and 1% bitumen (LCLB1) possessed compressive strength of 2.01N/mm2. It Water Absorption Capacity was 3.05%. LCLB4 stabilizer (90% laterite, 6% cement, 2% lime and 2% bitumen) has the same compressive strength with LCLB1 stabilizer but with a high Water Absorption Capacity of 4.2%. The stabilizer of 90% laterite, 3.33% cement, 3.33% lime and 3.33% of bitumen (LCLB8) has the lowest compressive strength of 0.74N/mm2 and the highest Water Absorption Capacity of 5.39%. The results shows that LCLB1 stabilizer is a better stabilizer for strength and blocks made from laterite stabilized with it stand a good alternative to sand Crete blocks in building constructions. The combination of these stabilizers in order to determine a most economical volume combination for optimum performance is highly possible and economical.

Surface Modification for Porous Artificial Lightweight Aggregate and Mechanical Properties of the Resulting Concrete

2011 ◽  
Vol 117-119 ◽  
pp. 1302-1305
Author(s):  
Ning Liao ◽  
Hong Zhi Cui
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Water Absorption ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
High Water ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
High Water Absorption ◽  
Change Material

This research is one part of preliminary work for integrated structural-functional energy storage concrete by using porous artificial lightweight aggregate and phase change material. Lightweight aggregate concrete (LWAC) has been applied more and more extensively in recent years, but high water absorption of porous artificial lightweight aggregate (LWA) is inconvenient for LWAC production. In order to improve LWA application, in this paper, two aspects of lightweight aggregate (LWA) study have been carried out, namely, a) LWA surface modification. The effects of different concentration of surface modifier on water absorption of modified LWA were studied. b) Mechanical properties of lightweight aggregate concrete made of the unmodified and modified LWAs Through comparing the water absorption of unmodified and modified LWAs, it can be known that the surface modification for LWA can reduce the water absorption obviously. The three kinds of lightweight concrete possess nearly same strength at 7-day and, at 28-day, the strength of LWAC using 1:20 modified LWA is highest and that of LWAC using 1:5 modified LWA is lowest. 28 days compressive strength of LWAC using 1:20 modified LWA could be up to 46.1MPa.

Villus-like nanocomposite hydrogels with a super-high water absorption capacity

2020 ◽  
Vol 8 (25) ◽  
pp. 12613-12622
Author(s):  
Xiaosai Hu ◽  
Qiao Wang ◽  
Qing Liu ◽  
Zongjin Li ◽  
Guoxing Sun
Keyword(s):  
Water Absorption ◽  
High Water ◽  
Absorption Capacity ◽  
Water Absorption Capacity ◽  
Nanocomposite Hydrogels ◽  
High Water Absorption

Villi-like structure greatly improved the water absorption capability of super water absorbing hydrogels (SAH).

Water Absorbing and Releasing of Lightweight Aggregate and its Influence on Frost-Resistance of Combined Aggregate Concrete

2011 ◽  
Vol 217-218 ◽  
pp. 51-56 ◽  
Author(s):  
Li Xiong Gao ◽  
Li Juan Kong ◽  
Yong Ge
Keyword(s):  
Water Absorption ◽  
Cement Paste ◽  
Frost Resistance ◽  
Lightweight Aggregate ◽  
High Water ◽  
Interfacial Zone ◽  
Aggregate Concrete ◽  
High Water Absorption ◽  
Dense Shell ◽  
Curing Age

Water absorbing and releasing property of lightweight aggregate (LWA) in concrete and its influence on microstructure of interfacial zone as well as frost-resistance of combined aggregate prepared with different water absorption LWA and w/b ratios were investigated. The results show that, as for concrete with low w/b ratio, the 28d frost-resistance of concrete prepared with high water absorption LWA is worse, however with the increase of curing age, the 90d frost-resistance of concrete improves obviously, which is due to the water releasing of LWA that leads to the recovery of its air entraining effect as well as the densification and thicken of interfacial zone. So the LWA with moderate water absorption should be selected to prepare the low w/b ratio concrete. As for concrete with high w/b ratio, the frost-resistance of concrete prepared with low water absorption LWA is the best. This is account for the dense shell of ceramsite that could reduce the soakage from loose cement paste under frozen pressure.

GENOTYPE RECOGNITION IN PEAS BY WATER IMBIBITION OF SEEDS

1966 ◽  
Vol 46 (5) ◽  
pp. 545-551 ◽  
Author(s):  
H. H. Marshall
Keyword(s):  
Water Absorption ◽  
Seed Weight ◽  
Sugar Content ◽  
High Water ◽  
Absorption Capacity ◽  
Water Absorption Capacity ◽  
Water Imbibition ◽  
High Water Absorption ◽  
Immature Seeds ◽  
Pea Seeds

Significant differences in the water absorption capacity of mature pea seeds were found between lines or varieties within and between each of four genetically different seed types, round, wrinkled, "new" wrinkled, and "double" wrinkled. The differences in water absorption were positively correlated with sugar content of immature peas. They were also negatively correlated with seed weight in lines with the genes for new wrinkled.Peas with both classical (rr) and the genes for new wrinkled have high water absorption indices and small seeds. Immature seeds contain from 14.6 to 17.0% sugar or about 1% more than classical wrinkled varieties.

scholarly journals Degradable tough chitosan dressing for skin wound recovery

2020 ◽  
Vol 9 (1) ◽  
pp. 1576-1585
Author(s):  
Yan Kong ◽  
Xiaoxuan Tang ◽  
Yahong Zhao ◽  
Xiaoli Chen ◽  
Ke Yao ◽  
...  
Keyword(s):  
Water Absorption ◽  
Wound Dressing ◽  
Antibacterial Properties ◽  
High Water ◽  
Skin Wound ◽  
Wound Dressings ◽  
Wound Recovery ◽  
Recovery And Healing ◽  
Optimized Treatment ◽  
Better Than

Abstract The performance of wound dressing determines the effect of wound closure and recovery. Water absorption and bacteriostasis of wound dressings play an important role in wound recovery and healing. In this study, an optimized chitosan wound dressing-tough chitosan dressing (TCS) with high water absorption, high bacteriostasis, and degradability was developed. The chemical structure of chitosan remained stable during the process of optimized treatment, and an increase in mechanical properties was obtained for the dressing. After optimization, the water absorption and antibacterial properties of the chitosan dressing were greatly improved, which is significantly better than sodium alginate dressing. The authors believe that TCS dressing with high hygroscopicity and high bacteriostasis has great potential application value in the field of wound recovery and healing.

scholarly journals Effect of Polypropylene Fiber on the Strength and Dry Cracking of Mortar with Coal Gangue Aggregate

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Kai Zhu ◽  
Xianwei Ma ◽  
Liyang Yao ◽  
Linlin Zhao ◽  
Chuangdan Luo
Keyword(s):  
Water Absorption ◽  
Polypropylene Fiber ◽  
High Water ◽  
Coal Gangue ◽  
Early Stages ◽  
Fine Coal ◽  
High Water Absorption ◽  
Dry Shrinkage ◽  
Compressive And Flexural Strengths ◽  
Cracking Risk

Fine coal gangue aggregate (CGA) has a high water absorption, which increases the cracking risk of mortar caused by dry shrinkage. The effects of polypropylene (PP) fiber on the fluidity, strength, dry shrinkage, and cracking of CGA mortar were studied in this paper. The results show that PP fiber reduces the fluidity of CGA mortar, but PP fiber improves compressive and flexural strengths, especially at the early stages. PP fiber also effectively decreases dry shrinkage and the risk of cracking. Overall, PP fiber can effectively improve the properties of CGA mortar.

scholarly journals UV polymerization and property analysis of maleacylated methyl cellulose acrylic acid absorbent resin

2020 ◽  
Vol 22 (2) ◽  
pp. 34-41
Author(s):  
Ying Li ◽  
Amatjan Sawut ◽  
Gongbo Hou ◽  
Mingyu He ◽  
Mamatjan Yimit
Keyword(s):  
Acrylic Acid ◽  
Water Absorption ◽  
Water Retention ◽  
Methyl Cellulose ◽  
High Water ◽  
Optimal Conditions ◽  
Synthetic Resin ◽  
Reaction Conditions ◽  
High Water Absorption ◽  
Maximum Water

AbstractIn this paper, maleic anhydride (MA) was grafted onto methyl cellulose (MC) and then reacted with acrylic acid to synthesize a high gel strength and fast water absorption resin (AA-co-MC-g-MA) by UV polymerization. The reaction conditions of maleylated methylcellulose (MC-g-MA) were investigated, including the ratio of MC to MA, reaction time and catalyst amount. In addition, the reaction conditions for the synthesis of super absorbent resin were as follows: the amount of MC-g-MA, the degree of substitution of MC-g-MA, polymerization time, and the amount of initiator. Under optimal conditions, the maximum water absorption volume of synthetic resin was 2116 g/g, and the maximum salt absorption rate was 139 g/g. The water absorption resin prepared this time had high water absorption, water retention, excellent pH sensitivity, etc. It was hoped that it will have a good application prospect in the field of industrial production and agriculture in the future.

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