## 3 Results
### Effects of CWP on Concrete Workability
Including Na\({}_{2}\)SiO\({}_{3}\) in Mix 2 led to a further reduction in slump, underscoring the importance of precise mixing proportions to achieve the desired workability in CWP concrete. [PERSON] et al. [68] investigated high-performance concrete containing CWP at 0-40% cement replacements. The researchers found that as the CWP replacement level in concrete increased, the initial slump value decreased, except for the 20% and 30% replacement levels. This decrease was attributed to the higher specific surface area of CWP, which was 1.5 times greater than that of cement. Furthermore, slump values decreased with time due to cement hydration, with the control mixture losing all slump within 60 min. However, the mixtures containing CWP demonstrated improved slump retention, with slump values reaching zero only around 120 min for the 20% replacement level. This improved slump retention was attributed to the limited immediate hydraulic reaction of CWP due to its low CaO content. Notably, the 40% CWP mixture exhibited a slump loss trend similar to that of the control mixture, possibly due to the very high surface area of CWP, especially at higher replacement ratios. [PERSON] et al. [44] found that the slump value of concrete decreases significantly when cement is partially replaced with CWP (Figure 6). Replacing 10% and 20% of cement with CWP resulted in slump decreases of 33.3% and 52.4%, respectively. The researchers stated that the irregular angular shape and higher specific surface area of CWP increased the friction between particles, leading to reduced slump values. The researchers also recommended the use of superplasticisers for CWP concrete to increase the slump value and workability by reducing the internal friction among concrete particles. Comparatively, a similar study by [PERSON] et al. [70] reported smaller changes in slump values with CWP increment, likely due to higher water/binder ratios and differences in aggregate properties used in their experiments [44]. These factors can also affect the workability of concrete. [PERSON] et al. [69] conducted three tests--slump flow, T50, and L- box to evaluate the impact of CWP on the filling ability of self-compacting concrete (SCC). Figure 7 shows the slump flow results. In contrast to compacted concrete, the slump flow test showed a significant increase in concrete workability with a higher CWP content replacing GGBS. As the CWP content increased from 0% to 80%, the flow diameter expanded from 560 to 780 mm, indicating enhanced flowability. The researchers stated that concrete mixes with 50-80% CWP met the European Federation of National Associations Representing Producers and Applicators of Specialist Building Products for Concrete (EFNARC) criteria for SCC. The T50 test results also reflected these findings. According to the study, concrete  
Figure 5: [PERSON] et al. Slump test results [28]. specimens demonstrated improved workability as the T50 time decreased from 6 s to 2.5 s with increasing CWP content. Mixes with 40% or more CWP replacement also met the EFNARC standards for SCC. The L-box test further confirmed these results, showing that all samples, except those with 0% and 10% CWP, passed the SCC requirements. The increased flowability was attributed to the larger particle size distribution and lower specific surface area of CWP compared to GGBS, as well as the lower water demand of CWP, which enhanced plasticity and workability by affecting the chemical reaction rate.