Effect of Wet Curing Duration on Long-Term Performance of Concrete in Tidal Zone of Marine Environment

Abstract

A proper initial curing is a very simple and inexpensive alternative to improve concrete cover quality and accordingly extend the service life of reinforced concrete structures exposed to aggressive species. A current study investigates the effect of wet curing duration on chloride penetration in plain and blended cement concretes which subjected to tidal exposure condition in south of Iran for 5 years. The results show that wet curing extension preserves concrete against high rate of chloride penetration at early ages and decreases the difference between initial and long-term diffusion coefficients due to improvement of concrete cover quality. But, as the length of exposure period to marine environment increased the effects of initial wet curing became less pronounced. Furthermore, a relationship is developed between wet curing time and diffusion coefficient at early ages and the effect of curing length on time-to-corrosion initiation of concrete is addressed.

Diffusion of chloride from seawater into the concrete analysis: a literature review on implemented approaches

“…The curve fitting has been done so that the chloride profiles are fitted where the correlation between the measured and fitted profiles has a maximum. Curve fitting has been performed following a procedure described in NordTest NT Build 443 and resulted in two regression parameters; a diffusion coefficient and surface chloride content [7]. Besides Fick's diffusion equation analysis method, there are some diffusion equation analysis methods such as Szweda's equation which is based on the expression determining the diffusion coefficient of chloride ions D 1 =1/Q − which is the reverse of the diffusion resistance of the entire tested concrete zone [9], Nernst-Einstein equation for porous materials such as concrete the diffusion coefficient formulation [10], Nernst-Planck equation numerical model based on the ionic coupling effects among ions in chloride solutions and ions in concrete pore solution, Na+, K+, OH- [11] and Bayesian inverse technique is used to estimate diffusion and migration coefficients of chloride in concrete treated as a saturated porous material [12].…”

“…-CP V RS [26], -w/c = 0.55 and 0.65 [11] -w/c = 0.32 [12] -OPC, HES, SCB*AL cement [3] -OPC, CEM I and CEM III/A [27] -w/c = 0,4 [28] -w/c = 0.4 -0.5 [29] -w/c = 0.30, 0.35, 0.40 and 0.45 [30] -PC equivalent to ASTM Type II [7] -w/c = 0.5 [31] [27] [7] -CEM I 42.5 N [24] -w/c = 0.55, 0.50, and 0.45 [25] -CEM IV/A-P 42.5R, CEM II/A-L 42.5R, and CEM III/A 42.5R [25] Water/Binder (W/B) ratio: Aggregate/cement ratios: 4 -6 [26] -W/B = 0.5 [3] -W/B = 0.4, 0.5, and 0.6 [5] Fly ashbinder ratios: 0.2, 0.35, and 0.5 [3] -W/B = 35%, 45%, 55% [15], -W/B = 0.47 [18] The volume fractions of coarse aggregate: -W/B = 0.4 and, 0,33 [24] -v = 0, 0.2, 0.3, 0.4, and 0.5. [15]…”

Long-Term Durability of Bio-Polymer Modified Concrete in Tidal Flooding Prone Area: A Challenge of Sustainable Concrete Materials

“…Several research have reported the durability of concrete structures in the marine environment, including long-term investigation of concrete performance exposed to seawater [3][4][5][6]. Furthermore, concrete mixed with seawater achieved a good mechanical properties performance even though it was slightly lower than those using plain water [7][8][9].…”

Quantitative measurement of the influence of degree of saturation on ion penetration in cement paste by using X-ray imaging

“…Concrete structures face many threats to their service life. A number of durability problems are caused by external fluids penetrating into cement-based materials [1][2][3][4]. These fluids can contain potentially harmful ionic species, can lead to damage from corrosion, sulfate attack, alkali silica reaction, bulk freeze thaw, and salt scaling [5][6].…”