Review study on the use of Boric Acid in concrete

This survey covers boric acid (H3BO3). Chemical structure of boric acid, H3BO3: The mortars including borogypsum waste had higher compressive and splitting tensile strengths and higher setting time with respect to reference sample which was borogypsum-free.it was seen that sample including 1% waste had the best splitting tensile strength (7.40 MPa) and sample including 3% waste had the best compressive strength (48.00MPa). According to results of non-calcined borogypsum experiments showed that sample including 5% waste had the best splitting tensile strength (7.63 MPa) and sample including 3% waste had the best compressive strength (45.70 MPa). they concluded that boric acid attack does not significantly affect the concrete structure. And boric acid had a negative effect on concrete strength development. Also,the rate of boric acid leaching, as with other concrete degradation mechanisms, depends in part on the rate of diffusive transport and compressive strength, expansion and setting time properties of cement decreased with the increase in B2O3 content of waste. Borogypsum is the waste that forms during boric acid production from the reaction between colemanite ore and sulphuric acid. Although borogypsum is used in many processes because of its B2O3 content it pollutes the soil and water. A long-term (2-year) investigation of rebar corrosion in reinforced concrete cracks penetrated by distilled water and boric acid solutions with pH 5.2 and 6.1 indicated a higher degree of corrosion in cracks with wider apertures and/or penetrated by water with lower pH