However, using high calcium fly ash, which may undergo both hydration and
pozzolanic reaction, compared to low calcium fly ash with only
pozzolanic reaction, is an added advantage in increasing concrete's long term strength development.
The
pozzolanic activity does improve the strength of the transition zone, i.e.
In contrast, much better durability and fiber anchorage was observed when cement clinker content was low and
pozzolanic fines are used, which decreases the alkalinity of the pore solution.
The strength of clayey soil-lime and clayey soil fly ash mixtures was improved as a result of enhancing the alkali
pozzolanic reaction in the mixtures [14, 15].
"Comparison of the strength and durability performance of normal- and high-strength
pozzolanic concretes at elevated temperatures." Cement and Concrete Research, Vol.
The microstructure analysis of old mortars reveals the different behaviors of pure lime and
pozzolanic mortars.
Incorporation of
pozzolanic materials in blended cements has been found to lower the permeability of aggressive ions such as chlorides.
Admixtures are effective materials for dry shrinkage control, reduction of hydration heat, and improvement of packing density, among others; in particular, admixtures are divided into cement-based materials, which harden by directly reacting with water, and
pozzolanic materials, which react with cement over time.
The second reaction is called secondary
pozzolanic reaction.
It also offers
pozzolanic, sulphur-resistant cement, and clinker, as well as provides cement finishing services.
Poor curing conditions are more adversely effective on the strength of concretes made by
pozzolanic cements than that of ordinary portland cement (OPC), and it is necessary to apply water curing to the former concretes at least for the initial 7 days to expose the
pozzolanic activity.