Investigating the Effects of Curing Methods on the Compressive Strength of Bitublock

• Published in: Journal of materials in civil engineering Vol. 22; no. 3; pp. 207 - 213
• Main Authors: Forth, J. P, Dao, D. V, Zoorob, S. E
• Format: Journal Article
• Language: English
• Published: American Society of Civil Engineers 01.03.2010
• Subjects: Aggregates; Aging; Asphalts; Binders; Bitumens; Bituminous; Civil engineering; Compacting; Compressive strength; Construction; Curing; Hardening; Masonry; Oxidation; Polymerization; Recycled; Recycling; TECHNICAL PAPERS; Viscoelastic materials; Wastes
• ISSN: 0899-1561; 1943-5533
• DOI: 10.1061/(ASCE)0899-1561(2010)22:3(207)

A novel construction unit (Bitublock) composed entirely of recycled and waste aggregates and bound with bituminous binders is currently being developed. At present, the manufacturing process requires the new units to be heat cured to convert the bitumen binder from a viscoelastic material into an elastic-brittle material (known as hardening or bitumen aging). The paper investigates the effect of aging and curing processes on the compressive strength of Bitublocks. In this investigation, samples were compacted at pressures of between 8 and 20 MPa and cured at temperatures of between 60 and 160°C for up to 48 h. Compressive strengths approaching 45 MPa were achieved. The range of compressive strengths achieved indicated that the behavior of the bituminous binder during heat curing significantly influences the performance of the Bitublocks and suggested that bitumen hardening is highly influenced by the curing temperature. Oxidation as opposed to polymerization and loss of volatiles was confirmed to be the key role in the bitumen hardening process (only approximately 7% of the total long-term hardening was due to volatilization). The oxidation process can be directly linked to the compressive strength development of Bitublock.