Rubblization of Portland Cement Concrete Pavements

Rehabilitation of existing pavements is a top pavement priority facing local, state, and federal transportation agencies. The use of hot-mix asphalt (HMA) overlays presents a long-term and economical solution to the pavement rehabilitation problem. HMA overlays restore rideability, improve the long-term functional pavement performance as well as increase the structural capacity of the existing pavement system. Due to the expense, time and traffic delay involved in concrete pavement restoration (CPR) and reconstruction, resurfacing of portland cement concrete (PCC) pavements with an HMA overlay is a very appealing option for many agencies. However, existing, worn-out PCC pavements present a particular problem for rehabilitation due to the likelihood of reflection cracking when an HMA overlay is placed. The reflection cracking problem must be addressed in the HMA overlay design phase if long-term performance of the overlay is to be achieved. The objective of rubblization is to eliminate reflection cracking in the HMA overlay by the total destruction of the existing slab action of the PCC pavement. This process is normally achieved by rubblizing the slab into fragments. Temperature and/or reinforcing steel, if present in the PCC pavement, is generally fully debonded from the concrete by this approach. The rubblization process is applicable to all types of existing PCC pavements. The objective of this paper is to provide an overview of current design and construction guidelines specific to the PCC rubblization process. A procedure is presented for determining the required thickness of an HMA overlay placed over rubblized PCC slabs as well as guidelines for construction.

AS 1012.9-1999 Methods of testing concrete - Determination of the compressive strength of concrete specimens

This Standard sets out the method for determining the compressive strength of concrete test specimens prepared in accordance with the provisions of AS 1012.8, AS 1012.14 or AS 1012.19.
NOTE: This Standard may involve hazardous materials, operations, and equipment. The Standard does not purport to address all of the safety problems associated with its use. The user of this Standard should establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

AS 1012.6-1999 Methods of testing concrete - Method for the determination of bleeding of concrete

This Standard sets out the method for determining the relative quantity of mixing water that will bleed from a sample of freshly mixed concrete under the conditions of the test. The Standard applies only to concrete in which the maximum aggregate size is 40 mm or less.
The Standard provides for compaction of the sample either by rodding or vibrating.
NOTES:
1 The results obtained will be dependent on the compaction method used.
2 This Standard may involve hazardous materials, operations, and equipment. The Standard does not purport to address all of the safety problems associated with its use. The user of this Standard should establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
3 Data on the precision of the test method were not available at the time of publication. This information will be included when available.

AS 1012.5-1999 Methods of testing concrete - Determination of mass per unit volume of freshly mixed concrete

This Standard sets out the method for determining the air content of freshly mixed concrete using the volumetric method.
This Standard is suitable for concrete made with any type of aggregate, whether it be dense, cellular or lightweight.
NOTES:
1 This Standard may involve hazardous materials, operations, and equipment. The Standard does not purport to address all of the safety problems associated with its use. The user of this Standard should establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2 Data on the precision of the test method were not available at the time of publication. This information will be included when available.

Design of Wind Turbine Foundation Slab