# A Detailed Review on Foam Concrete Composites: Ingredients, Properties, and Microstructure
## 3 Properties of Fresh Foam Concrete  
### Workability  
With the increase in density, the spread of light concrete increases. Foam concretes with low densities have high foam content. Therefore, the mixtures become harder, causing a decrease in the settling flow [5,21]. The use of fiber reduces the workability of foam concrete, and it may be necessary to increase the amount of superplasticizer to provide workability [47]. The increase in the w/c ratio causes the water film on the particles to thicken. Thus, the viscosity decreases, and the diffusion of foam concrete increases [72].  
In the study where ceramics thinner than 4.75 mm were used, the ceramics were partially replaced by river sand. The ceramics used have high water absorption capacity. For this reason, it was observed that some of the water used to maintain the fluidity of the mixture tends to be retained by the ceramics. This situation caused the slump values to decrease [73]. Similarly, in [PERSON] et al. [5]'s study, waste marble powder was used as a fine aggregate partially replacing sand and it was observed that WMP reduced the slump values. It was reported that the reason for this is the angular grain structure of WMP aggregates. Due to its angular shape, more surface area has to be lubricated, which reduces workability [5]. The small diameter of the aggregate used increases the aggregate surface area. Increased surface area causes more water demand and reduces workability. Inert dust has a smaller particle diameter than sand and using inert dust instead of sand reduces workability. Superplasticizers should be used in order to achieve the desired workability. For this reason, it is difficult to obtain foam concrete with a high dust content [35]. The use of superplasticizer provides the desired workability with the presence of low water content [16]. Workability characteristics reported for different flow values are given in the Table 4.  
\begin{table}
\begin{tabular}{c c c} \hline
**References** & **Fiber Type** & **Effect** \\ \hline \multirow{2}{*}{[63]} & Steel & The use of steel fiber has significantly increased ductility and rupture modulus. However, it did not have a significant effect on compressive strength. \\ \cline{2-3}  & Polypropylene & Polypropylene fiber increased tensile strength and modulus of rupture. There was no significant effect on compressive strength and flexibility modulus. \\ \hline \multirow{2}{*}{[49]} & Polypropylene & It improved the strength of foamed concrete. It reduced workability. It improved drying shrinkage. \\ \hline \multirow{2}{*}{[64]} & PVA & It significantly improved mechanical behavior. \\ \hline \multirow{2}{*}{[65]} & Nylon & It increased the ductility index. \\ \hline \multirow{2}{*}{[66]} & Natural (Miscanthus) & It increased its compressive strength. It was reported that a sustainable geopolymer concrete can be developed with thermal insulation. \\ \hline \multirow{2}{*}{[67]} & Polypropylene & The geopolymer foam reduced the drying shrinkage of the concrete and increased the compressive and bending strength. \\ \hline \multirow{2}{*}{[68]} & Rice straw & It contributed to the development of acoustic and thermal properties. \\ \hline \multirow{2}{*}{[69]} & Cellulose & It increased compressive strength by 35\%, increased the stability of the foamed concrete mix and reduced shrinkage deformation. \\ \hline \multirow{2}{*}{[70]} & Hemp & It provided very large compressive and flexural strength enhancements. \\ \hline \multirow{2}{*}{[5]} & Basalt & The flexural and compressive strengths increased. \\ \hline \multirow{2}{*}{[71]} & Glass & Improved the bending capacity of the beams. \\ \hline \end{tabular}
\end{table}
Table 3: Some examples of fiber reinforced foam concrete studies.