Fine light weight aggregate, because they serve as an internal source of water.

I recommend that you read Jonathan Kerby's thesis (University of Arkansas, Fayetteville).

Most of the aggregate will have tendency to absorb water and this absorbed water in aggregate is the result of Saturated Surface Dry (SSD) condition of aggregates. Desiccation of this water for curing purpose will be very difficult in initial curing period when the required humidity for curing is very high . This water will desiccate over a long period out of aggregate and concrete and in a very long period the gain of strength because of this will be minimum as by this time cement particle outer layer will have hydrated and very small internal core of cement particle will remain un-hydrated. For this un-hydrated part, it will be difficult to make use of this water for curing and gain strength.

However, excess water that is more than SSD condition will probably be available out of fine aggregate if these are crystalline in nature like river bed sand. In case light weight aggregate is porous and if it can easily desiccate its water then probably this may help in curing.

Any way quite interesting question and look forward to more expert comments.

Hi dear Divyata Thakare

What do you mean by "internal curing"?

I think fine aggregate with a goog grading is more useful to internal curing or self-curing

For internal curing..it is better to work with , any additive. working with aggregate absorption as parameter for internal curing does not yield any good results...and there is no evident for self curing..

Generally fine aggregate are preferred for two main reasons: a better distribution of the "internal" curing water throughout the concrete microstructure and less detrimental influence on concrete compressive strength as larger lightweight aggregates usually imply larger pores within those aggregates which may limit compressive strength development.

Absolutely fine aggregate for two reasons, good dispersion within matrix, neglected effect on compressive strength as coarse aggregate

Hi, you will fined interesting results regarding the use of fine LWA in the following papers:

Weber, S.; Reinhardt, H.-W., A Blend of Aggregates to Support Curing of Concrete, in International Symposium on Structural Lightweight Aggregate Concrete, Holand, I.; Hammer, Tor A. and Fluge, F., Editors. 1995, Norwegian Concrete Association: Sandefjord, No

Takada, K.; van Breugel, K.; Koenders, E.A.B. and Kaptijn, N., Experimental evaluation of autogenous shrinkage of lightweight aggregate concrete, in Autogenous Shrinkage of Concrete, Tazawa, E.-i., Editor. 1999, CRC Press. pp. 241–250.

Lura, P.; Jensen, O.M. and Igarashi, S.-I., Experimental observation of internal water curing of concrete. Materials and Structures, 2007. 40(2): pp. 211-220.

Yehia, S.; AlHamaydeh, M. and Farrag, S., High-Strength Lightweight SCC Matrix with Partial Normal-Weight Coarse-Aggregate Replacement: Strength and Durability Evaluations. Journal of Materials in Civil Engineering, 2014. 26(11): pp. 04014086.

Ferrara, L.; Cortesi, L. and Ligabue, O., Internal Curing Of Concrete With Presaturated LWA: A Preliminary Investigation, in ACI SP 305 - Durability & Sustainability of Concrete Structures, Chiorino, M.A. et al., Editors. 2015, ACI Italian Chapter: Bologna (Italy). pp. 12.1-12.12.

Cusson, D.; Hoogeveen, T., Internal curing of high-performance concrete with pre-soaked fine lightweight aggregate for prevention of autogenous shrinkage cracking. Cement and Concrete Research, 2008. 38(6): pp. 757-765.

It is better work on some other techniques... check out RILEM work published on self curing agents.

How to ensure self curing mechanism is working in conventional concrete. As we know strength is not deciding parameters, as we know it will be affected by planty factors..can suggest ideal methodology

in my research project, I work on sand concrete where the diameter of the coarse aggregate is equal to 5mm, the characteristics of this concrete are close to and sometimes exceed those of conventional concrete.