Title:
Effects of Reduced Paste Content and Base Restraint on Young Concrete Pavement
Author(s):
D. G. Mapa, A. Markandeya, A. Sedaghat, N. Shanahan, H. DeFord, K. A. Riding, and A. Zayed
Publication:
Materials Journal
Volume:
115
Issue:
5
Appears on pages(s):
663-673
Keywords:
bond breaker; concrete pavement repair; jointed plain concrete pavement; paste content reduction; stressmeter
DOI:
10.14359/51702241
Date:
9/1/2018
Abstract:
Jointed plain concrete pavement (JPCP) replacement slabs can experience early-age cracking from early-age volume change.
These slabs are often made of high-early-strength (HES) concrete characterized by high cement content and low water-cement ratio (w/c), which can result in large temperature rise and high levels of autogenous shrinkage, and ultimately an elevated cracking potential. This study investigated the effects of reduced paste content and base restraint minimization on reducing concrete early-age cracking potential. The effect of each of these measures was evaluated in place by measuring the stress and temperature development in concrete test slabs instrumented with concrete stressmeters and thermocouples. Calorimetry studies and mechanical properties testing were used with modeling software to assess field trends. The findings indicated that it is possible to achieve higher strengths and lower stresses with low-paste mixtures. Changes in concrete stress during the first 24 hours after placement, due to moisture loss to the base, were seen in slabs with polyethylene sheet or geotextile fabric underneath the slab.