Author: Cold Regions Research and Engineering Laboratory (U.S.)Publisher:
ISBN:
Category :
Languages : en
Pages : 27
Book Description
Cold Weather Construction Materials - Part 1 : Field Validation of Laboratory Tests on Regulated - Set Cement for Cold Weather Concreting
Author: Cold Regions Research and Engineering Laboratory (U.S.)Publisher:
ISBN:
Category :
Languages : en
Pages : 27
Book Description
Cold Weather Construction Materials, Part 2
Author: B. J. HoustonPublisher:
ISBN:
Category : Cement
Languages : en
Pages : 34
Book Description
The Army carries on construction projects in localities where the concrete placing season is shortened considerably by the cold climate. This study evaluates regulated-test cement, which is a fast setting, rapid strength gain cement, that appeared to have great promise and would allow concrete to be placed at ambient temperatures as low as 15 F. Both mortars and concretes made with regulated-set cement were studied in the laboratory with favorable results, so the laboratory results were validated with field testing. Two 12-ft by 12-ft by 8-in. test slabs were cast in January 1975 when the mean ambient temperature was approximately 15 F. The only differences in the two slabs were the concrete mixture temperature and air entrainment. The slabs received no special protection from the ambient temperatures. Neither slab obtained any appreciable compressive strength at 1 day but slab 1 had approximately 1200 and 2000 psi at 7 and 28 days, respectively, while slab 2 had 2200 and 3300 psi, respectively. The concrete in both slabs was wetter than intended. Since there was no strength gain at day 1, whereas there had been in laboratory tests of approximately the same concrete mixture but with an earlier shipment of regulated-set cement, a sample of cement from the field test was brought to the laboratory for comparison with the cement used in the laboratory tests. Chemical and physical tests indicated that there was a difference in chemical composition; the laboratory shipment had a higher sulfate content. This difference points out the need for a responsive purchase specification, which is presently not available. Keywords: Cold regions; Regulated set concrete.
Cold Weather Construction Materials
Author: Billy J. HoustonPublisher:
ISBN:
Category : Cement
Languages : en
Pages : 42
Book Description
Cold Weather Construction Materials
Author: Billy J. HoustonPublisher:
ISBN:
Category : Building
Languages : en
Pages : 36
Book Description
Cold Weather Construction Materials
Author: Billy J. HoustonPublisher:
ISBN:
Category : Cement
Languages : en
Pages : 27
Book Description
Cold Weather Construction Materials. Part 2. Regulated-Set Cement for Cold Weather Concreting. Field Validation of Laboratory Results
Author: Billy J. HoustonPublisher:
ISBN:
Category :
Languages : en
Pages : 38
Book Description
The U.S. Army carries on construction projects in localities such as Alaska, the northern tier of the United States, northern Europe, and the Arctic where the concrete placing system is shortened by the cold climate. At ambient temperatures below 50 F, concreting operations become more expensive since Corps of Engineers specifications require freshly mixed and placed concrete to be protected from low ambient temperatures. The overall military construction and maintenance in cold regions program was initiated to locate and evaluate existing and new cementing materials that would allow concrete to be placed at ambient temperatures as low as 15 F.A relatively newly developed cement called 'regulated-set' cement, which is a fast setting, rapid strength gain cement, appeared to have promise and was selected for a detailed study. (Author).
Cold Weather Construction Materials
Author: Billy J. HoustonPublisher:
ISBN:
Category :
Languages : en
Pages : 28
Book Description
The U.S. Army carries on construction projects in localities such as Alaska, the northern tier of the United States, northern Europe, Greeland and other arctic sites where the concrete placing season is shortened considerably by the cold climate. At ambient temperatures below 50 F, concreting operations become considerably more expensive since U.S. Army Corps of Engineers specifications require freshly mixed and placed concrete to be protected from ambient temperatures. This report covers part of an investigation to locate and evaluate existing and new cementing materials that allow concrete to be placed at ambient temperatures as low as 15 F.A newly developed cement termed regulated-set cement, which is an accelerated set cement, appeared to have great promise and was selected for study in this stage of the investigation. Both mortars and concretes made with regulated-set cement were studied with the following results: (1) The longer freshly mixed regulated-set cement concrete remains above freezing before exposure to below freezing temperatures the greater the subsequent early strength gain; however, considerable strength gain was exhibited by specimens exposed at 15 F immediately after casting. Specimens protected one hour before exposure exhibited almost as much strength at 28 days age as specimens cured at 70 + or - 3 F for the full time; and (2) The heat development in 3-, 6-, and 12-in.-thick slabs exposed at 15 F immediately after casting peaked in one to two hours at 46.5, 58 and 69 F, respectively, and remained above freezing long enough to gain considerable strength.
Cold Weather Construction Materials
Author: Billy Joe HoustonPublisher:
ISBN:
Category : Building
Languages : en
Pages : 0
Book Description
The U.S. Army carries on construction projects in localities such as Alaska, the northern tier of the United States, northern Europe, Greeland and other arctic sites where the concrete placing season is shortened considerably by the cold climate. At ambient temperatures below 50 F, concreting operations become considerably more expensive since U.S. Army Corps of Engineers specifications require freshly mixed and placed concrete to be protected from ambient temperatures. This report covers part of an investigation to locate and evaluate existing and new cementing materials that allow concrete to be placed at ambient temperatures as low as 15 F.A newly developed cement termed regulated-set cement, which is an accelerated set cement, appeared to have great promise and was selected for study in this stage of the investigation. Both mortars and concretes made with regulated-set cement were studied with the following results: (1) The longer freshly mixed regulated-set cement concrete remains above freezing before exposure to below freezing temperatures the greater the subsequent early strength gain; however, considerable strength gain was exhibited by specimens exposed at 15 F immediately after casting. Specimens protected one hour before exposure exhibited almost as much strength at 28 days age as specimens cured at 70 + or - 3 F for the full time; and (2) The heat development in 3-, 6-, and 12-in.-thick slabs exposed at 15 F immediately after casting peaked in one to two hours at 46.5, 58 and 69 F, respectively, and remained above freezing long enough to gain considerable strength.
Scientific and Technical Aerospace Reports
Author: Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 764
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
USA CRREL Benchnotes
Author: Cold Regions Research and Engineering Laboratory (U.S.)Publisher:
ISBN:
Category : Cold regions
Languages : en
Pages : 218
Book Description