scholarly journals Corrigendum to “Study on the Mitigative Effect of Controlled Permeable Formwork (CPF) Liner on Early-Age Shrinkage of Box-Girder Concrete”

2020 ◽  
Vol 2020 ◽  
pp. 1-1
Author(s):  
Jianxiong Ye ◽  
Linwen Yu ◽  
Yong Chen
Keyword(s):  
2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jianxiong Ye ◽  
Linwen Yu ◽  
Yong Chen

Because of its high binder content and severe construction environment, early-age cracking is one of the most important threats to concrete used in continuous box-girder bridge structures. In this study, controlled permeable formwork (CPF) liner was used to mitigate the early-age shrinkage and reduce the early-age cracking risk of box-girder concrete. Early-age shrinkage was measured by a noncontact method and started at 30 min after adding mix water until 7 d. Internal relative moisture content and pore distribution tests were also carried out to reveal the working mechanism of CPF liner. The results show that covering the concrete surface with CPF liner decreased early-age shrinkage significantly. Under the temperature of 20°C and the relative humidity of 60%, two-surface-covering and three-surface-covering CPF liner on concrete decreased the shrinkage by 44% and 48%, respectively, at 7 d compared with concrete without CPF liner covered on it. The main reason is that CPF liner enhanced the internal relative moisture content and resulted in better performance of the surface concrete.


2013 ◽  
Vol 470 ◽  
pp. 1045-1050
Author(s):  
Wei Gang Sun ◽  
Lai Jun Liu ◽  
Qun Hu Wu ◽  
Jian Ping Feng

The temperature stress is one of the main reasons for early age cracking of concrete under low temperatures,it has the actual value of reference for the design and construction of concrete structures to study the regularities of hydration heat temperature of concrete box girder in low-temperature environment. Therefore, through the test of concrete box girder hydration heat temperature, this paper analyses the temp-time curves of temperature of the concrete box-bridge cross section. The results can be used for concrete temperature control and/or cracking control of box girder in similar environmental area.


1982 ◽  
Vol 47 (4) ◽  
pp. 373-375 ◽  
Author(s):  
James L. Fitch ◽  
Thomas F. Williams ◽  
Josephine E. Etienne

The critical need to identify children with hearing loss and provide treatment at the earliest possible age has become increasingly apparent in recent years (Northern & Downs, 1978). Reduction of the auditory signal during the critical language-learning period can severely limit the child's potential for developing a complete, effective communication system. Identification and treatment of children having handicapping conditions at an early age has gained impetus through the Handicapped Children's Early Education Program (HCEEP) projects funded by the Bureau of Education for the Handicapped (BEH).


Sign in / Sign up

Export Citation Format

Share Document