Concrete is the most used man-made material globally and its consumption is expected to be 25 giga tonnes every year. The fresh concrete waste is estimated to be 330 million metric tonnes. Allowing the slurry from the RMC to the settling tank and landfill often has a negative impact on society. Recent scientific reports on concrete slurry waste (CSW) suggest that CSW has the potential to be used as a building material and is capable of sequestering CO₂. Therefore, a lack of comprehensiveness in CSW has been observed regarding its material behaviour and fresh and hardened behaviour in paste/mortar. The current study aims to conduct a state-of-the-art review on the physico-chemical properties of both carbonated and non-carbonated CSW. This report assesses the morphology, mineralogy phases, and thermogravimetric analysis (TGA) on CSW powder. Along with this, the fresh properties, hydration mechanics, hardening behaviour, and porosity behaviour of CSW in paste and mortar are intellectually summarised as supplementary cementitious material (SCM). Consequently, the CSW fines possess the ability to uptake 17–24% of CO₂ and have a carbonation degree of 48.3%. Substituting 10% to 20% of CSW as SCM primarily results in a filler effect, dilution effect, and nucleus effect. Moreover, this innocuous and eco-friendly pathway suggests the CSW should be recommended as a performance-improving SCM.