Durability of Portland Concrete Containing Polymeric Fillers and Fly Ash

Abstract

Portland concrete suffers in service brittle failure, extensive crack propagation, and wear rates increasing with time. In spite of all the effort expended, these problems persisted when we had started our project. We used several polymeric fillers and fly ash. Higher compressive moduli than the starting concrete are seen for some compositions, the highest for 5 % of one of the polymers + 5 % fly ash. The same composition has the lowest Taber abrasive wear loss. All composites show lower wear loss values than Portland concrete. After 25 days of acidic degradation in 4.0 molar aq. HCl, the starting Portland concrete suffers stronger degradation that our composites. Polymer swelling mitigates acidic degradation. Repetitive freeze-thaw cycles between 15oF and 85oF show disappearance of the deep voids present before the first cycle in our composites—but not in the Portland cement. While the use of fly ash mitigates contamination of the environment, it is the combination of fly ash with polymers which provides significantly improved properties - tribological, chemical and mechanical ones – of the Portland concrete.

Adsorption Performance of Modified Fly Ash for Copper Ion Removal from Aqueous Solution

“…This type of material contains principally SiO 2 and Al 2 O 3 [1], elements that recommend the use of ash in a large spectrum of applications. For example, it is used for zeolite synthesis [2,3], as catalysts [4], in construction as filler or as a precursor for geopolymers [5][6][7], as an adsorbent [8][9][10][11], for ceramics [12,13], etc. Thus, many studies were involved in order to find a solution that would allow its utilization.…”

Numerical Simulation of the Effect of Freeze–Thaw Cycles on the Durability of Concrete in a Salt Frost Environment

“…In Formula (2), m is the density of the system; c is the specific heat capacity of the system; T is temperature; t represents time; p is the thermal conductivity of the system; and α is the thermal conductivity of the system. In the porous system, the relationship between effective stress and strain is as follows [16]:…”