Protected Paste Volume in Concrete Extension to Internal Curing Using Saturated Lightweight Fine Aggregate. Communication.
Protected Paste Volume in Concrete Extension to Internal
Curing Using Saturated Lightweight Fine Aggregate.
Bentz, D. P.; Snyder, K. A.
Cement and Concrete Research, Vol. 29, No. 11,
aggregates; concretes; microstructure; protected paste
One difficulty in the field use of high-performance
concrete is the extensive self-desiccation and
autogenous shrinkage that may occur due to its low
water/cement ratio and the addition of silica fume to
the mixture proportions. Several researchers have
proposed the use of saturated lightweight aggregates to
provide "internal" curing for the concrete. In this
communication, simple equations are developed to
estimate the replacement level needed to ensure adequate
water for complete curing of the concrete.
Additionally, a three-dimensional concrete
microstructural model is applied to determine the
fraction of the cement paste within a given distance
from the lightweight aggregate surfaces. The simulation
results are compared with analytical approximations
developed previously. This new concept for curing is
similar to the protected paste volume concept
conventionally applied to characterizing air void
systems in air-entrained concrete.