**6. Conclusions**

The CWP contains high silica and alumina content (i.e., >80%). Also, it is characterized by having some amorphous content which shows pozzolanic activity especially at late ages. Therefore, CWP has strong potentials to be used as an ingredient in making eco-friendly concretes.

Using CWP as an ingredient in making CVC is viable. High-performance concrete can be produced by including CWP as partial cement replacement. CWP improves the workability retention of the CVC mixtures. The inclusion of CWP will reduce the early-age strength and slowed the strength development. Significant improvement of CVC durability can be achieved by including high content of CWP. The CVC performance varies according to the CWP content. CWP can be used in the range of 10–20% to improve workability retention and late strength development. A CWP content ranging from 30 to 40% is needed to improve durability. If the performance of mixture requires the combination of workability retention, strength and durability, a CWP content ranging from 20 to 30% can be used to optimize all required characteristics.

CWP can be used as a partial cement replacement to produce SCC that meets international requirements. All fresh concrete properties, except for slump flow, are significantly improved by the incorporation of CWP. The improvement is proportional to the CWP content. Similar to CVC, the inclusion of CWP affected the strength development and enhanced the durability. SCC with improved fresh performance and optimized strength can be produced using 40% CWP as partial cement replacement.

The use of CWP in making AAC showed promising potentials. The production of AAC using CWP should consider the aggregate content of the mixture, the use of superplasticizer admixtures and the use of an alkali solution composed of NaOH and KOH. The combination of slag with CWP improves the workability and strength development without the need for long curing time to conserve energy. The combination of CWP with fly ash can also be an alternative to enhance the performance of the produced AAC.

Finally, CWP has encouraging potentials to be used as an ingredient to make eco-friendly conventional-vibrated concrete (CVC), self-compacting concrete (SCC) and zero-cement alkali-activated concrete (AAC). The concrete industry can and will play a vital role in the sustainable development through the utilization of industrial waste materials.
