Effects of Cellulose Ether on Homogeneity of Concrete in Structures — Relating Quality Variations and Construction Joints

1986 ◽  
pp. 125-133 ◽  
Author(s):  
T. Soshiroda ◽  
K. Hayakawa ◽  
K. Yoda ◽  
M. Tanaka
Keyword(s):  
Cellulose Ether ◽  
Construction Joints

Arminou Dam, Cyprus, and construction joints in diaphragm cut-off walls

Géotechnique ◽  
2002 ◽  
Vol 52 (1) ◽  
pp. 3-13 ◽  
Author(s):  
A. J. Brown ◽  
D. A. Bruggemann
Keyword(s):  
Construction Joints

scholarly journals Rheological properties of hydroxypropylmethyl cellulose/sodium dodecylsulfate mixtures

2014 ◽  
Vol 79 (4) ◽  
pp. 457-468 ◽  
Author(s):  
Jaroslav Katona ◽  
Sandra Njaradi ◽  
Verica Sovilj ◽  
Lidija Petrovic ◽  
Brankica Marceta ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Sodium Dodecylsulfate ◽  
Shear Thinning ◽  
Cellulose Ether ◽  
Flow Profile ◽  
Hydroxypropylmethyl Cellulose ◽  
Shear Rates ◽  
Newtonian Liquids ◽  
Shear Induced Structure ◽  
Induced Structure

Rheological properties of mixtures of hydroxypropylmethyl cellulose (HPMC), a nonionic associative cellulose ether, and sodium dodecylsulfate (SDS), an anionic surfactant, were investigated by viscosity measurements performed at different shear rates (0.1-6000 s-1). HPMC/SDS mixtures containing different concentrations of SDS (CSDS=0.00-3.50 % w/w) and HPMC concentrations which corresponded to the overlap parameter c/c*=3, 6, and 12 were prepared. All HPMC/SDS mixtures were found to be shear-thinning when examined in a low-end-to mid-range of the applied shear rates. The degree of shear-thinning, n, and viscosity of the mixtures were influenced by composition of HPMC/SDS mixtures and HPMC-SDS complex formation. The changes in n ranged from values typical for highly shear thinning to almost perfectly Newtonian liquids, and were more pronounced as c/c* was increased from 3 to 6 and 12. A change in flow profile and a buildup of the first normal stress difference (N1) was observed in HPMC/SDS mixtures with c/c*=6 and 12 and CSDS 0.55-1.00 % and 0.55-2.50 %, respectively, when a critical shear rate, crit. was exceeded, suggesting that a shear-induced structure formation in the mixtures took place.

Flexible Thermoplastic Cellulose Ether Composites

2016 ◽  
Vol 48 (3) ◽  
pp. 212-216 ◽  
Author(s):  
A. A. Karpukhin ◽  
S. E. Panicheva ◽  
T. V. Kuznetsova ◽  
A. A. Kalinichev
Keyword(s):  
Cellulose Ether

Numerical Limit Analysis of Slab Bridges with Construction Joints

2018 ◽  
Author(s):  
Thomas Westergaard Jensen ◽  
Linh Cao Hoang
Keyword(s):  
Carrying Capacity ◽  
Limit Analysis ◽  
Concrete Slabs ◽  
Load Carrying Capacity ◽  
Layer Model ◽  
Yield Criteria ◽  
Reinforced Concrete Slabs ◽  
Load Carrying ◽  
Construction Joints

The conic yield criteria for reinforced concrete slabs in bending are often used when evaluating the load‐carrying capacity of slab bridges. In the last decades, the yield criteria combined with numerical limit analysis have shown to be efficient methods to determine the load carrying capacity of slabs. However, the yield criteria overestimate the torsion capacity of slabs with high reinforcement ratios and it cannot handle slabs with construction joints. In this paper, numerical limit analysis with the conic yield criteria are compared with yield criteria based on an optimized layer model. The analysis show an increasing overestimation of the load carrying capacity for increasing reinforcement degrees. Furthermore, yield criteria, which combine the conic yield criteria with an extra linear criterion due to friction, are presented for slab bridges with construction joints. The yield criteria for slabs with construction joints are used, in combination with limit analysis, to evaluate a bridge constructed of pre‐cast overturned T‐beams and in‐situ concrete. The analysis show that the load carrying capacity is overestimated, when the construction joints are not considered in the yield criteria.

Influence of Aluminous Cement on the Hardening Rate of Cement-Based Stucco Mortars

2016 ◽  
Vol 865 ◽  
pp. 57-61 ◽  
Author(s):  
Wojciech Siemiński ◽  
Marcin Kaczmarczyk
Keyword(s):  
Portland Cement ◽  
Setting Time ◽  
Experimental Studies ◽  
Cellulose Ether ◽  
Hydrophobic Properties ◽  
Content Ratio ◽  
Flow Table ◽  
Aluminous Cement ◽  
Hydrophobic Nature ◽  
The Impact

Renovation mortars used to restore damaged stucco elements are materials with special physical properties due to the nature of the work and environment in which they are applied. They must be characterized by low shrinkage, relatively short setting time, appropriate working properties and hydrophobic nature of hardened mortar. This paper analyzes the impact of mortar stucco ingredients on these parameters. The analysis was performed by experimental studies. The effect of the content ratio of aluminate cement to Portland cement on the change in mortar setting time was studied. Suitable workability of fresh mortar is achieved by the use of consistence-modifying additives. To assess this parameter, flow table method was applied in accordance with PN-EN 1015-3: 2000. The additives used were a system of thickeners, which included: cellulose ether in the form of hydroxyethylmethylcellulose and modified starch ether (starch 2-hydroxypropyl ether). Hydrophobic properties were obtained by the addition of triethoxyoctylsilane. The results were presented as graphs and tables. It was found that the ratio of aluminous cement to Portland cement most beneficial in terms of the setting rate of the resulting stucco mortar is 25% (m/m). This amount accelerates the end of setting time to 2 hours, the beginning of the setting time being 20 minutes. Suitable working characteristics were obtained by the addition of 0.080% of hydroxyethylmethylcellulose and 0.025% (m/m in dry mix) of starch 2-hydroxypropyl ether. Best hydrophobic properties of the hardened mortar was obtained by the addition of 0.075% (m/m in dry mix) of triethoxyoctylsilane.

scholarly journals Double Resonance Method for Determination of Gel Point

2019 ◽  
pp. 160-165
Author(s):  
Ivan S. Kozhevnikov ◽  
Lyubov K. Altunina ◽  
Andrey V. Bogoslovsky ◽  
Lyubov A. Stasyeva
Keyword(s):  
Double Resonance ◽  
Resonance Method ◽  
Gel Point ◽  
Cellulose Ether ◽  
Different Diameters

The application of double resonance method for determining the dynamics of fluidity changes of thermotropic gel-forming compositions based on cellulose ether is considered. To determine the gel point, a modified version of the ‘Rheokinetika’ viscometer including two identical sensors and measuring cells of different diameters

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