Effect of Piezoelectric Ring Sensor Size on Early-Age Property Monitoring of Self-Consolidating Concrete

2018 ◽  
Vol 115 (6) ◽  
Author(s):  
Siwar Naji ◽  
Kamal H. Khayat ◽  
Mourad Karray
Keyword(s):  
Early Age ◽  
Self Consolidating Concrete ◽  
Property Monitoring

scholarly journals Effect of temperature on early-age properties of self-consolidating concrete equivalent mortar

2020 ◽  
Vol 5 ◽  
pp. 114-122
Author(s):  
Nima Farzadnia ◽  
Jing Pan ◽  
Kamal Khayat ◽  
Eric Wirquin
Keyword(s):  
Heat Flux ◽  
Compressive Strength ◽  
Effect Of Temperature ◽  
Early Age ◽  
Test Results ◽  
Hydration Kinetics ◽  
Self Consolidating Concrete ◽  
Air Content ◽  
Cementing Material ◽  
Material Temperature

In this study, the effect of material temperature during casting on fresh properties, hydration kinetics, and early-age compressive strength of self-consolidating concrete (SCC) was evaluated. Concrete equivalent mortars (CEMs) based on SCC mixture designs with water-to-binder ratios of 0.41 and 0.45 were investigated. The SCC mixtures are targeted for infrastructure and building construction and precast applications. The CEMs were prepared at temperatures ranging from 8 to 36°C.  Superplasticizer (SP) and air-entraining agent (AEA) demand were evaluated for the CEM mixtures made with different supplementary cementing material (SCM) and limestone filler types. Test results showed that the ambient temperature can significantly affect the SP and AEA demand, hydration kinetics, and compressive strength after 1 d of age. According to the ultraviolet–visible spectrophotometry (UV/Vis) test, the absorption rate of polycarboxylate-based SP decreased with temperature. In contrast, the sensitivity of polynaphthalene sulfonate-based SP to temperature was minimal. Relationships between the variations of different admixture contents, heat flux, and compressive strength with temperature were developed. For a constant slump flow and air content, the demand of the SP and AEA, heat flux, and 1-d compressive strength of CEMs increased linearly with material temperature.

Early-Age Cracking of Self-Consolidating Concrete with Lightweight and Normal Aggregates

2018 ◽  
Vol 30 (10) ◽  
pp. 04018242 ◽  
Author(s):  
Aleksandra Radlińska ◽  
Maria Kaszyńska ◽  
Adam Zieliński ◽  
Hailong Ye
Keyword(s):  
Early Age ◽  
Self Consolidating Concrete

A Community Based High Risk Register for Hearing Loss

1982 ◽  
Vol 47 (4) ◽  
pp. 373-375 ◽  
Author(s):  
James L. Fitch ◽  
Thomas F. Williams ◽  
Josephine E. Etienne
Keyword(s):  
Hearing Loss ◽  
System Identification ◽  
High Risk ◽  
Language Learning ◽  
Education Program ◽  
Communication System ◽  
Auditory Signal ◽  
Early Age ◽  
Community Based ◽  
Children With Hearing Loss

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).

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