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Hot Bituminous Materials

Hot-mix bituminous materials, such as coated macadams and hot rolled asphalt, are used in roadbase, basecourse and wearing course road construction. New hot mixes such as porous asphalt, stone mastic asphalt and hot thin surfacings have also been introduced into Ireland.


The binder content and aggregate grading of hot mixes should be checked regularly for compliance with the relevant job specification. An initial rate of sampling of 1 sample per 100 tonnes is recommended for these materials.


The compaction of coated macadams is assessed with the percentage refusal density (PRD) test using cored specimens. The compaction density can also be readily monitored using a nuclear density gauge.


The new hot mix materials have introduced new testing procedures including the water sensitivity test, binder drainage test and cantabro wear test.


Highway Testing Laboratory Ltd. can design, test and certify the quality of both standard and new hot bituminous materials for use in road construction. The range of tests which we perform are listed below:


Hot Bituminous Material Tests:

Hot Bituminous Materials

On-site Quality Control (laying records, temps, etc.)

Sampling of Materials

Binder Content and Aggregate Grading

Core Cutting

Percentage Refusal Density (PRD)

Nuclear Density Gauge Testing

Quality of Coated Chippings

Rate of Spread of Coated Chippings

Texture Depth (Sand Patch Method)

Moisture Sensitivity Test

Binder Aggregate Affinity Test

Binder Drainage Test

Marshall Air Voids

Cantabro Wear Test


The standard tests for assessing hot bituminous materials are performed in accordance with the following:

B.S. 598 "Sampling and Examination of Bituminous Materials"

B.S. 4987 "Coated Macadams"

B.S. 594 "Hot Rolled Asphalt"

Department of the Environment "Specifications for Road Works"

NRA Provisional Specifications and CEN Draft Specifications

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