Effects of Moisture, Temperature, and Freezing and Thawing on Alkali-Silica Reaction

2018 ◽  
Vol 115 (4) ◽  
Author(s):  
Richard A. Deschenes ◽  
Eric Giannini ◽  
Thano Drimalas ◽  
Benoit Fournier ◽  
W. Micah Hale
Keyword(s):  
Alkali Silica Reaction ◽  
Freezing And Thawing

Mitigation of Alkali-Silica Reaction and Freezing and Thawing through Surface Treatment

2017 ◽  
Vol 114 (2) ◽  
Author(s):  
Richard A. Deschenes ◽  
Cameron D. Murray ◽  
W. Micah Hale
Keyword(s):  
Surface Treatment ◽  
Alkali Silica Reaction ◽  
Freezing And Thawing

scholarly journals Durability of concrete containing aggregate produced from recycled concrete affected by alkali-silica reaction

2021 ◽  
Author(s):  
Chris Christidis
Keyword(s):  
Coarse Aggregate ◽  
High Reactivity ◽  
Recycled Concrete ◽  
Alkali Silica Reaction ◽  
Concrete Aggregate ◽  
Freezing And Thawing ◽  
Salt Scaling ◽  
And Control ◽  
Minimal Information ◽  
Durability Of Concrete

Minimal information is available on the durability of concrete containing demolished concrete as an aggregate. The purpose of this study was to: investigate and control the reactivity of recycled concrete aggregate (RCA) produced from concrete that was suffering from alkali silica reaction (ASR); and investigate other durability issues of concrete containing RCA with emphasis on salt scaling and freezing & thawing. It was deduced that the RCA produced from ASR-affected concrete caused expansion when used in new concrete as an aggregate. This high reactivity of the tested RCA was attributable to its relatively high alkalis and calcium contents. Furthermore, a greater amount of SCM was required to reduce expansion compared to concrete containing raw natural reactive aggregate. In terms of freezing and thawing and salt scaling, concrete containing coarse RCA at a 100% replacement level of coarse aggregate showed lower durability compared to concrete made with natural coarse aggregate.

Mitigating Alkali-Silica Reaction and Freezing and Thawing in Concrete Pavement by Silane Treatment

2018 ◽  
Vol 115 (5) ◽  
Author(s):  
Richard Deschenes ◽  
Eric R. Giannini ◽  
Thano Drimalas ◽  
Benoit Fournier ◽  
W. Micah Hale
Keyword(s):  
Concrete Pavement ◽  
Alkali Silica Reaction ◽  
Silane Treatment ◽  
Freezing And Thawing

Effectiveness of sealers in counteracting alkali-silica reaction in highway median barriers exposed to wetting and drying, freezing and thawing, and deicing salt

2002 ◽  
Vol 29 (2) ◽  
pp. 329-337 ◽  
Author(s):  
Marc-André Bérubé ◽  
Dominique Chouinard ◽  
Michel Pigeon ◽  
Jean Frenette ◽  
Michel Rivest ◽  
...  
Keyword(s):  
Salt Water ◽  
Alkali Silica Reaction ◽  
Freezing And Thawing ◽  
Wetting And Drying ◽  
Deicing Salt ◽  
Concrete Members ◽  
Aesthetic Appearance ◽  
Concrete Cylinders ◽  
The Aesthetic ◽  
High Alkali

This study follows another experimental study where different types of sealers were applied on plain and air-entrained large concrete cylinders made with high-alkali contents and highly alkali–silica reactive limestone aggregates. The main objective was to determine the effectiveness of these sealers in counteracting concrete expansion and surface deterioration due to alkali–silica reaction under various exposure conditions. This study indicated that all three sealers tested, the silane-, oligosiloxane-, and polysiloxane-based sealers, could stop concrete expansion due to ASR and even produced contraction, even for concrete cylinders subjected to wetting and drying, freezing and thawing, and sodium chloride solutions. In 1991, the same silane, oligosiloxane, and polysiloxane were applied on sections of median barriers showing various degrees of deterioration due to ASR. These sections were subjected to wetting and drying, freezing and thawing, and, during winter, to deicing salt. The silane was also applied on other sections of the same barriers in 1994. Observations and measurements over 10 years indicate that the aesthetic appearance of these median barriers, particularly those sealed with the silane, was greatly improved, while internal humidity was significantly reduced, and concrete expansion as well, when not arrested. The period of time during which the above three sealers were capable to stop ASR expansion varies with the sealer used and the degree of concrete deterioration at the time of sealing. For instance, the silane, which was the best among all products tested, caused concrete contraction for at least 6 years in median barriers that were severely affected by ASR, and likely for more than 10 years in moderately affected barriers. The overall results confirm the conclusions obtained previously in the laboratory: a good sealer such as the silane tested may greatly improve the aesthetic appearance and stop the expansion of non-massive ASR-affected concrete members, at least up to about 300 mm in thickness, and subjected to wetting and drying, freezing and thawing, and salt water. However, the poor result obtained in the field with another silane-based sealer indicates that a sealer cannot be selected based on its composition only.Key words: alkali–silica reaction, concrete; cracking, expansion, internal humidity, median barrier, sealer, silane, siloxane.

Effectiveness of sealers in counteracting alkali-silica reaction in plain and air-entrained laboratory concretes exposed to wetting and drying, freezing and thawing, and salt water

2002 ◽  
Vol 29 (2) ◽  
pp. 289-300 ◽  
Author(s):  
Marc-André Bérubé ◽  
Dominique Chouinard ◽  
Michel Pigeon ◽  
Jean Frenette ◽  
Luc Boisvert ◽  
...  
Keyword(s):  
Salt Water ◽  
Linseed Oil ◽  
The Other ◽  
Alkali Silica Reaction ◽  
Freezing And Thawing ◽  
Wetting And Drying ◽  
Surface Cracking ◽  
Air Content ◽  
High Alkali ◽  
Freezing And Thawing Cycles

Low- and high-alkali, plain and air-entrained large concrete cylinders, 255 mm in diameter by 310 mm in length, were made with a highly alkali–silica reactive limestone. After curing, a number of cylinders were sealed with silane, oligosiloxane, polysiloxane, linseed oil, or epoxy, with others subjected to 179 freezing and thawing cycles in humid air (one cycle per day). All cylinders were then subjected to 14-day exposure cycles, including in the most severe case periods of humid storage in air, drying, wetting in salt water, and freezing and thawing cycles. All low-alkali specimens did not either expand or develop surface cracking, even those with a deficient air void system and exposed to freezing and thawing cycles. All unsealed high-alkali cylinders subjected early to a series of freezing and thawing cycles did not significantly expand during these cycles, but presented high expansion afterwards. Wetting and drying significantly reduced alkali–silica reaction (ASR) expansion compared with constant humid storage; however, it promoted map-cracking. Regardless of the air content, freezing and thawing increased greatly the concrete expansion in the presence of ASR, even after ASR was almost complete; freezing and thawing also greatly promoted surface cracking. On the other hand, all cylinders early sealed with silane, oligosilixane, or polysiloxane did not either significantly expand or show map-cracking, whatever the exposure conditions and the air content; these cylinders progressively lost mass with time. On the other hand, the epoxy resin was not effective. The linseed oil prevented map-cracking while significantly reducing expansion, however not sufficiently. After one or 1.5 years, some expanding cylinders were sealed with silane, oligosiloxane, or polysiloxane; they started to loose mass and contracted immediately after being sealed, whatever the exposure conditions. The results obtained thus indicate that a good sealer may greatly improve the aesthetic appearance (e.g., map-cracking) and stop expansion of ASR-affected concrete elements of 255 mm or less in thickness, made with a water-to-cement ratio in the range of 0.50, and exposed to wetting and drying, freezing and thawing, and salt water.Key words: air entrained, alkali–silica reaction, concrete, cracking, expansion, freezing and thawing, sealer, silane, siloxane, wetting and drying.

scholarly journals Durability of concrete containing aggregate produced from recycled concrete affected by alkali-silica reaction

2021 ◽  
Author(s):  
Chris Christidis
Keyword(s):  
Coarse Aggregate ◽  
High Reactivity ◽  
Recycled Concrete ◽  
Alkali Silica Reaction ◽  
Concrete Aggregate ◽  
Freezing And Thawing ◽  
Salt Scaling ◽  
And Control ◽  
Minimal Information ◽  
Durability Of Concrete

Minimal information is available on the durability of concrete containing demolished concrete as an aggregate. The purpose of this study was to: investigate and control the reactivity of recycled concrete aggregate (RCA) produced from concrete that was suffering from alkali silica reaction (ASR); and investigate other durability issues of concrete containing RCA with emphasis on salt scaling and freezing & thawing. It was deduced that the RCA produced from ASR-affected concrete caused expansion when used in new concrete as an aggregate. This high reactivity of the tested RCA was attributable to its relatively high alkalis and calcium contents. Furthermore, a greater amount of SCM was required to reduce expansion compared to concrete containing raw natural reactive aggregate. In terms of freezing and thawing and salt scaling, concrete containing coarse RCA at a 100% replacement level of coarse aggregate showed lower durability compared to concrete made with natural coarse aggregate.

Three-Dimensional Structure of Cloned T3 Connector Protein at 1.6nm Resolution

1990 ◽  
Vol 48 (1) ◽  
pp. 282-283
Author(s):  
José L. Carrascosa ◽  
José M. Valpuesta ◽  
Hisao Fujisawa
Keyword(s):  
Dna Sequences ◽  
Expression Vector ◽  
Three Dimensional ◽  
Deae Cellulose ◽  
Dna Packaging ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Freezing And Thawing ◽  
Three Dimensional Structure ◽  
Dimensional Reconstruction

The head to tail connector of bacteriophages plays a fundamental role in the assembly of viral heads and DNA packaging. In spite of the absence of sequence homology, the structure of connectors from different viruses (T4, Ø29, T3, P22, etc) share common morphological features, that are most clearly revealed in their three-dimensional structure. We have studied the three-dimensional reconstruction of the connector protein from phage T3 (gp 8) from tilted view of two dimensional crystals obtained from this protein after cloning and purification.DNA sequences including gene 8 from phage T3 were cloned, into Bam Hl-Eco Rl sites down stream of lambda promotor PL, in the expression vector pNT45 under the control of cI857. E R204 (pNT89) cells were incubated at 42°C for 2h, harvested and resuspended in 20 mM Tris HC1 (pH 7.4), 7mM 2 mercaptoethanol, ImM EDTA. The cells were lysed by freezing and thawing in the presence of lysozyme (lmg/ml) and ligthly sonicated. The low speed supernatant was precipitated by ammonium sulfate (60% saturated) and dissolved in the original buffer to be subjected to gel nitration through Sepharose 6B, followed by phosphocellulose colum (Pll) and DEAE cellulose colum (DE52). Purified gp8 appeared at 0.3M NaCl and formed crystals when its concentration increased above 1.5 mg/ml.

Factor VIII-Related Activities in Normal, Haemophilic and von Willebrand’s Disease Platelet Fractions

1978 ◽  
Vol 40 (02) ◽  
pp. 288-301 ◽  
Author(s):  
P Meucci ◽  
I R Peake ◽  
A L Bloom
Keyword(s):  
Factor Viii ◽  
Electrophoretic Mobility ◽  
Concanavalin A ◽  
Freezing And Thawing ◽  
Von Willebrand's Disease ◽  
Factor Viii Related Antigen ◽  
Von Willebrand’S Disease ◽  
Normal Plasma ◽  
Significant Difference ◽  
Ristocetin Cofactor

SummaryFactor VIII-related activities have been studied in platelet fractions in order to try to reconcile the conflicting findings of other workers, and to extend the studies. In platelets from 16 normal subjects procoagulant factor VIII was not detected. The amount of factor VIII-related antigen (FVIIIR: AG) in the cytosol per mg of protein was about twice that in the membrane fraction and about ten times that in the debris fraction. There was no significant difference between the amount of FVIIIR: AG and ristocetin cofactor (RistCof) activity in each fraction. The findings in haemophilic platelets were similar. In von Willebrand’s disease (vWd) one serverely affected patient had no detectable factor VIII related activities in any platelet fraction. In 5 patients with intermediate vWd results were normal. In a further 5, with more prolonged bleeding times, no FVIIIR: RistCof was detected in platelets, despite a normal amount of FVIIIR: AG in the cytosol and debris. The electrophoretic mobility of cytosol FVIIIR: AG was increased in all normals and patients, while that in the membrane and debris fractions had normal mobility. Cytosol FVIIIR: AG eluted later than normal FVIIIR: AG on gel filtration on Sepharose 2B, and also showed reduced antibody binding in an immunoradiometric assay. Precipitation of FVIIIR: AG by concanavalin A was incomplete in all platelet fractions from normals, and even more reduced in vWd platelet fractions. The results suggest the possibility of two types of platelet FVIIIR: AG.A factor VIII-related antigen was shown to be associated with normal washed platelets by immunofluorescence techniques (Bloom et al. 1973). Since then, several studies have been reported on the localisation of factor VIII related antigen (FVIIIR: AG), factor VIII procoagulant activity (FVIII: C) and factor VIII related ristocetin cofactor activity (FVIIIR: RistCof) within the platelets. Initially, Howard et al. (1974) indicated that FVIIIR: AG was firmly bound to the platelet membrane, and noted that in lysed platelets the level of FVIIIR: AG as measured by electroimmunodiffusion was higher than that in whole platelet suspensions. However, further studies by Nachman and Jaffe (1975) showed that FVIIIR: AG was also present to a considerable extent in the granules, and they detected none in the platelet cytosol. Bouma and colleagues (1975) were, however, able to find FVIIIR: AG and FVIIIR: RistCof in the cytosol upon freezing and thawing platelets. This FVIIIR: AG had an electrophoretic mobility comparable to that of normal plasma. They also noted that platelets which were air dried apparently had a granular FVIIIR:AG localisation by immunfluorescence; however, intact platelets in suspension did not stain by this method.Recently Ruggeri et al. (1977) and Sultan et al. (1977) have also found FVIIIR: AG in the cytosol, and the former authors reported it to have increased electrophoretic mobility when compared to normal plasma FVIIIR:AG. Results concerning the localisation of FVIIIR: AG in normal platelets have thus been conflicting. Similarly, in the few reports available concerning platelet FVIIIR: AG in von Willibrand’s disease variable results have also been obtained (Ruggeri et al. 1977, Howard et al. 1974, Shearn et al. 1974 and Bouma et al. 1975).In this study we report on the localisation of factor VIII-related activities in normal, haemophilic and von Willebrand’s disease platelets using available standard techniques as well as precipitation of FVIIIR: AG with the plant lectin concanavalin A, a procedure which has been shown to detect abnormal forms of FVIIIR:AG in certain types of von Willebrand’s disease (Peake and Bloom 1977).

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