Mitigate the curing problems of concrete pavements by using heated non-expansive clay particles as internal curing agent

Abstract

Internal curing concrete can be used in the production of concrete road pavements, bases, etc. It reduces the formation of drying shrinkage cracks and saves lots of money and time that spend on ineffective external curing processes. Unfortunately, internal curing aggregates (ICAs) are not available in most countries. Thus the production of internal curing concrete (ICC) is limited to a few countries. This research focuses on developing an effective ICA using non-expansive clay type. Consequently, a non-expansive clay type was selected and heated at various temperatures ranging from ${800}^{\circ }\mathrm{C}$ to ${1300}^{\circ }\mathrm{C}$ at intervals of ${100}^{\circ }\mathrm{C}$. Afterwards, heated clay samples were crushed into fine aggregates. The optimum heating temperature which gives the required properties as ICA was identified as ${900}^{\circ }\mathrm{C}$ through an extensive analysis followed by pore structure of heated clay aggregates. The produced aggregate achieved $1.8\mathrm{g}/{\mathrm{c}\mathrm{m}}^3$ density value, 15.5% of water absorption. Subsequently, ICC achieved higher compressive strength and workability more than the conventional concrete without any external curing process. Moreover, the aggregate reduced the drying shrinkage of concrete.

Keywords:

• internal curing
• non-expansive clays
• porous structure
• water absorption
• sand replacement
• compressive strength

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

M. M. H. W. Bandara  http://orcid.org/0000-0001-8966-5794

Additional information

Funding

This research was funded by the University of Moratuwa, Sri Lanka, under (SRC/LT/2016/02) grant.