Eco - Concrete made with phosphogypsum-based super sulfated cement

Abstract

Phosphogypsum is an important environmental issue for all countries with phosphate and phosphoric acid industries from phosphate rock. The problem mainly stems from the difficulty in storing phosphogypsum. Therefore, the reuse of phosphogypsum in producing construction materials plays an important role to protect human health, to decrease the environmental pollution and to reduce the building materials cost. This research aimed at developing an eco concrete using super sulfated cement (SSC) in which the phosphogypsum was recycled. The present paper deals with the experimental investigation on slump number of fresh concrete, 28-day compressive strength characteristics of concrete using only 10% cement, 30% - 60% phosphogypsum and granulated blast furnace slag in binders named super sulfated cement with 3 different water-binder ratios of 0.45, 0.50 and 0.55... It is shown that Portland cement can be replaced with super sulfated cement based on Vietnam phosphogypsum to develop a good and hardened concrete to achieve economy; The compressive strength of concrete can achieve 20-40MPa. This value is enough for the use of the eco-concrete in the construction industry. The results also indicate that the increase of replacement of phosphogypsum in concrete lead to reduction in the compressive strength but do not affect too much in the case of slump number.