BOND PROPERTIES OF LIGHTWEIGHT AGGREGATE CONCRETE

A series of tests was carried out to study the bond strength and anchorage length of reinforcement in lightweight aggregate concrete. This work formed part of a research project carried out at TRL Limited on behalf of the UK Highways Agency. This paper presents the following: results of mixing trials to obtain concrete of reasonable strength (greater than 40N/mm2) and workability, using two lightweight aggregates (Lytag and Pellite) and one normal weight aggregate; results of pull-out tests to determine bond strength and anchorage lengths for reinforcement embedded in lightweight aggregate concrete (LWAC) It was found that, in general, the concrete strength achieved with Lytag aggregate was greater than that for Pellite. At 28 days, the strength of the Lytag and the normal weight concrete were very similar. The pull-out test revealed that the bond strengths for each of the LWACs were lower compared with those for normal weight concrete. The load-slip curves obtained from the pull-out test showed that generally, the mode of failure was a slip mechanism at the bar-concrete interface. The results also showed that the minimum anchorage requirements in BS 5400: Part 4 are adequate for LWAC. Furthermore the results suggested that, at least for deformed bars, the 0.8 reduction factor for bond values for LWAC is not required. This supports the view that LWAC can be a viable alternative to normal weight concrete (NWC). (A)

• Corporate Authors:

  TRL

  Crowthorne House, Nine Mile Ride
  Wokingham, Berkshire  United Kingdom  RG40 3GA
• Authors:
  • OFORI-DARKO, F K
• Publication Date: 2000

Language

• English

Media Info

• Features: References;
• Pagination: 9 p.

Subject/Index Terms

• TRT Terms: Adhesion; Aggregates; Concrete; Failure; Lightweight materials; Strength of materials
• ITRD Terms: 5942: Adhesion; 4577: Aggregate; 4755: Concrete; 5520: Failure; 9038: Lightweight; 5544: Strength (mater)
• Subject Areas: Geotechnology;

Filing Info

• Accession Number: 00928836
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Aug 2 2002 12:00AM