###### Abstract
The passing ability and segregation resistance of SCC are achieved by the decrease in coarse aggregate content and increases in the powder quantities. The superplasticizers (high-range water reducers) are responsible for the high fluidity of the concrete mix, while the powder and viscosity-modifying agents lead to better stability and cohesion, reducing bleeding and segregation of the mix. Mineral admixtures are used as extra-fine material; the most used is the limestone filler which represents a chemically inert by-product of limestone crushers. The addition of limestone powder improves the particle packing by filling the small pores between cement grains and augmenting the water retention of fresh mixes. The compressive strength is calculated by the failure load divided by the cross-sectional area resisting the load and reported megapascals (MPa). Concrete hardens and acquires strength as it hydrates. This process occurs rapidly at first and slows down as time goes by; it continues over a long period.. This study investigated the compressive strength at 28 days, an age considered for design purposes when a substantial percentage of hydration has taken place. The cube and cylinder strength of SCC and conventional vibrated concrete was determined at the same w/c ratio and cement content [12; 13]. To ascertain the compressive strength of SCC modified with FA, several cylindrical or cubical specimens are currently produced and tested over various curing times in the practice field. Generally speaking, work on the construction site should not continue until the results of the compressive strength test at a given age, particularly 28 days, are available. Due to this, testing takes longer than expected and is more expensive [14]. Construction sites are also delayed as a result. Fly ash can replace 40% of the cement in self-compacting concrete to increase its strength to 65 MPa [10]. The term \"binder content\" refers to the cement and any additional pozzolanic elements that may be included in the mixture to enhance specific SCC characteristics. FA is additionally one of the most reactive pozzolanic materials. With an increase in cement or binder content, the compressive strength of SCC was typically noticeably enhanced [4; 15]. When the amount of cement was increased from 360 to 450 kg/m\({}^{3}\) at the same water content, the compressive strength of SCC increased from 48 and 52 MPa to roughly 52 and 60 MPa at 28 and 90 days, respectively [16; 17; 18]. The w/c or w/b ratio, similar to normal concrete, is one of the key factors affecting the CS of SCC at different curing ages. Compared to regular concrete, SCC frequently has a lower w/b ratio. When the w/b ratio is lower, a higher percentage of cement and binder ingredients produces a higher CS and a more homogeneous matrix [4]. The w/c or w/b ratio, similar to normal concrete, is one of the key factors affecting the CS of SCC at different curing ages. Compared to normal concrete, SCC frequently has a lower w/b ratio. When the w/b ratio is lower, a higher proportion of cement and binder ingredients produces a higher CS and a more homogeneous matrix. When the w/b ratio was decreased from 0.45 to 0.35 up to 56 days of curing, the CS of SCC was significantly improved at all curing ages [19]. The w/b ratio affects the CS of regular concrete more so than it does the CS of SCC [20]. One of the main advantages SCC has over other special concrete varieties is that it does not need any special curing procedures. Similar to regular concrete, SCC is cured using the same procedure. According to earlier studies [4; 21], the most crucial factor affecting the CS of SCC is the age of the concrete samples after the examination. Longer curing times produced better compressive strength for the same mix proportions because of the faster rate of hydration. The CS of SCC was increased from 13 MPa to 54 MPa by extending the curing time from one day to 28 days, as demonstrated by [PERSON] and [PERSON] [22]. According to [PERSON] et al. [23], the 7-day CS of SCC was 55.9 MPa.