Load transfer from high-strength concrete columns through lower strength concrete slabs

Six specimens were tested to investigate the effects on high strength concrete columns due to the presence of ordinary strength floor concrete layer in between. The specimens consisted of four sandwiched type of columns and two edge columns. The four columns, 55 in. long, had a 7 in. layer of floor concrete. These column specimens were designed to study the influence of longitudinal as well as lateral steel on the strength characteristics and behavior of the floor concrete. Two edge columns specimens consisted of two column sections separated by a 7 in. floor slab extending beyond the column faces in three directions. The data from these tests combined with the previously reported similar studies was analyzed to find the appropriate parameters for the estimation of the apparent strength of the floor concrete to be used in the calculation of load carrying capacity of columns. The analysis reveals that Sec. 10.13 of the ACI code is not based on the appropriate parameters. The allowable ratio of 1.4 between the two concrete strengths within which there is no requirement to reduce the column capacity is not considered appropriate. Similarly, the calculation of the apparent floor concrete strength in case of interior columns as per Sec. 10.13.3 was also found to be too unconservative.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Civil and Environmental Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Kayani, M. Khaliq-ur-Rashid

Contributors dc:contributor

• Gamble, William L.

• Engineering, Civil
• Engineering, Materials Science

Statement dc:rights

• Copyright 1992 Kayani, M. Khaliq-ur-Rashid

Language dc:language

eng

Identifier

AAI9215836
(UMI)AAI9215836

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/23462