scholarly journals Corrosion Effect of Rice Husk Ash in Concrete Pore Solution: Response Surface Analysis

2020 ◽  
Vol 14 (1) ◽  
pp. 162-173
Author(s):  
Busari Ayobami ◽  
Kupolati Williams ◽  
Loto Tolulope ◽  
Sadiku Emmanuel ◽  
Jacques Snyman ◽  
...  

Background: Corrosion of reinforcement impedes the structural integrity of concrete infrastructures by reducing the flexural, shear and axial strength of concrete, thereby making it structurally weak. Aim: This research assessed the corrosion effect of rice husk as a concrete constituent for the design of long-lasting concrete infrastructures. Materials and Methods: To achieve the aim of this research, rice husk was air-dried for two days and then burnt at a temperature of 600oC. It was used as a partial replacement for cement at 0%, 10%, 20% and 30% replacement of cement. The concrete pore solution was extracted by mechanical means. This was used as the medium to assess the weight loss and calculate the corrosion rate at seventy-two (72) hours interval with a focus on the temperature of the environment. The corrosion inhibition of the steel rebar was determined using the weight loss method. Results: The result was analysed and modelled using a response surface analysis. The optimisation of the corrosion effect was also assessed using the same method. The result of the study revealed that the inhibition efficiency based on the average corrosion rate was -69.54%, which indicates that 5% of rice husk ash does not inhibit corrosion, likewise the other replacements. The corrosion inhibition of 15% replacement with rice husk ash is slightly higher than the control sample. The research revealed that the most favourable replacement in terms of corrosion rate in comparison to the other percentages is 15%. Conclusion: The mathematical model showed that RHA has a positive effect on the corrosion rate of mild steel. This indicates that the higher the RHA, the lower the corrosion rate. The outcome of this research will serve as a guide for concrete users, engineers, corrosion experts and researchers on the use of rice husk ash in concrete production.

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2709
Author(s):  
Mohd Salahuddin Mohd Basri ◽  
Faizal Mustapha ◽  
Norkhairunnisa Mazlan ◽  
Mohd Ridzwan Ishak

As a result of their significant importance and applications in vast areas, including oil and gas, building construction, offshore structures, ships, and bridges, coating materials are regularly exposed to harsh environments which leads to coating delamination. Therefore, optimum interfacial bonding between coating and substrate, and the reason behind excellent adhesion strength is of utmost importance. However, the majority of studies on polymer coatings have used a one-factor-at-a-time (OFAT) approach. The main objective of this study was to implement statistical analysis in optimizing the factors to provide the optimum adhesion strength and to study the microstructure of a rice husk ash (RHA)-based geopolymer composite coating (GCC). Response surface methodology was used to design experiments and perform analyses. RHA/alkali activated (AA) ratio and curing temperature were chosen as factors. Adhesion tests were carried out using an Elcometer and a scanning electron microscope was used to observe the microstructure. Results showed that an optimum adhesion strength of 4.7 MPa could be achieved with the combination of RHA/AA ratio of 0.25 and curing temperature at 75 °C. The microstructure analysis revealed that coating with high adhesion strength had good interfacial bonding with the substrate. This coating had good wetting ability in which the coating penetrated the valleys of the profiles, thus wetting the entire substrate surface. A large portion of dense gel matrix also contributed to the high adhesion strength. Conversely, a large quantity of unreacted or partially reacted particles may result in low adhesion strength.


2014 ◽  
Vol 38 (3) ◽  
pp. 934-941 ◽  
Author(s):  
Gláucia Oliveira Islabão ◽  
Ledemar Carlos Vahl ◽  
Luís Carlos Timm ◽  
Donald Luiz Paul ◽  
Aline Hernandez Kath

Rice husk ash (RHA) is a by-product from the burning of rice husk that can have favorable effects on the soil in terms of acidity correction. The objectives of this study were to determine the effective calcium carbonate equivalent (ECC) of RHA under field conditions, and establish technical criteria as a basis for estimating the overall ECC of RHA. The 12 treatments of the experiment consisted of 10 RHA dosages (0, 10, 20, 30, 40, 60, 80, 100, 120, and 140 Mg ha-1) and two references, one of which was an absolute control (AC) and the other a plot limed and fertilized according to official recommendations (recommended fertilization - RF). The soil was sampled twice (15 and 210 days after incorporating RHA), in the layers 0.00-0.10 and 0.10-0.20 m, to determine the pH(H2O) and base saturation (V%). The ECC and neutralizing value (NV) of RHA were also determined. The results showed that RHA neutralizes soil acidity, in a faster reaction than conventional limestone, despite a low ECC (around 3 %).


2011 ◽  
Vol 233-235 ◽  
pp. 648-651
Author(s):  
Ai Jun Wei ◽  
Bei Feng ◽  
Xin Zhang ◽  
Fu Yong Huo

In this corrosion test, simulated brine is used as corrosion medium, added different concentrations of aloe juice. Static weight-loss method is employed, meanwhile, we calculated corrosion rate of Q235 steel and researched on the corrosion inhibition effect of aloe in different temperatures. Results show that aloe is a good inhibitor, rate of corrosion inhibition can reach 80% or more and suitable for the temperature of work environment is less than 60 °C.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
G. Salinas ◽  
J. G. Gonzalez-Rodriguez ◽  
J. Porcayo-Calderon ◽  
V. M. Salinas-Bravo ◽  
M. A. Espinoza-Medina

The hot corrosion behavior of Fe40Al intermetallic alloyed with Ag, Cu, Li, and Ni (1–5 at.%) in NaCl-KCl (1 : 1 M) at 670°C, typical of waste gasification environments, has been evaluated by using polarization curves and weight loss techniques and compared with a 304-type stainless steel. Both gravimetric and electrochemical techniques showed that all different Fe40Al-base alloys have a much higher corrosion resistance than that for stainless steel. Among the different Fe40Al-based alloys, the corrosion rate was very similar among each other, but it was evident that the addition of Li decreased their corrosion rate whereas all the other elements increased it. Results have been explained in terms of the formation and stability of an external, protective Al2O3layer.


2010 ◽  
Vol 6 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Didik Prasetyoko ◽  
Zainab Ramli ◽  
Salasiah Endud ◽  
Halimaton Hamdan ◽  
Bogdan Sulikowski

White rice husk ash obtained from complete uncontrolled burning of rice husk contains more than 94% silica. The ash, which consists of crystalline silica of the type tridymite and a-crystobalite, was used directly as a source of silica in the synthesis of zeolite beta. The mole oxide ratio of the initial gel of 1.25-8Na2O: 10-120SiO2: Al2O3: 1-20TEA2O: 150-1000H2O was prepared and heated at 150°C in a static condition for 6 d. The solid phases formed were monitored by XRD technique. Influence of reaction mixture ratio in the initial gel to the crystalline products formed was studied. Results showed that the pure zeolite beta was formed in a certain range of reaction mixture, i.e.: 1.25-4Na2O : 15-45SiO2 : Al2O3 : 4-10TEA2O : 240-480H2O. The other ratio of reaction mixtures produced crystalline phases such as analcime, Na-P, mordenite, and gismondine, and non-reacted of a-crystobalite and tridymite. Keywords: rice husk ash, tridymite, a-crystobalite, zeolite beta, synthesis


2020 ◽  
Vol 2 (1) ◽  
pp. 48-61
Author(s):  
Sang Kee ◽  
Yuhee Park ◽  
Eun Choi

This study was experimental in nature and conducted with the view to make comparison between two samples. The first sample consisted of concrete with rice husk ash mixed in it and the other sample was without such addition. The first test conducted to test the performance was simple measurements. The results show that for the sample without addition of rice husk ash, the density was 2355.97 and for included sample, the density was 2354.44 with insignificant differences (t-stat= 0.766, P>.05). For V-B test, the sample without addition of rice husk as was 8.34 and for include sample, it was 8.01. The differences for V-B for both samples were statistically insignificant (t-stat=1.431, P>.05). The slump test without for the sample without addition of rice husk was 12.75 and for included sample, it was 18.56. The difference was statistically significant (t-stat=2.455, P<.05). The compressive strength for excluded sample was 24.32 and for included sample was 20.01. The results were statistically insignificant (t-value= 1.13, P>.05). For flexural strength test, for excluded sample, the average score was 9.02 and for included sample, the average score was 9.19. The difference was statistically insignificant (t-stat=1.45, P>.05). Overall, the results lead to the conclusion that there are insignificant differences of addition of rice husk ash in concrete.


Author(s):  
Antonio Carlos Rodrigues ◽  
Ricardo Silveira Martins

ABSTRACT Context: studies argue that similar levels of dependence are essential for supplier satisfaction in buyer-supplier relationships. However, asymmetric relationships can also lead to supplier satisfaction. Objective: this paper investigates the effects of benefit-based dependence (positive motivations for maintaining relationships) between buyer and supplier and supplier satisfaction. Methods: response surface analysis (RSA) was used to test the relationship between third-party logistics (3PL) dependence and satisfaction dimensions in 174 dyads. Results: the results demonstrated that about supplier satisfaction, instead of dependence asymmetry what really matters is the degree of dependence between the parties. The more dependent one part is on the other, usually, the greater the supplier’s satisfaction. In many circumstances, a degree of dependence is acceptable and necessary to access resources and opportunities. Conclusions: the interaction between buyer and supplier dependence and supplier satisfaction is complex. Situations of dependence asymmetry in which the supplier is highly dependent on the buyer may still be satisfactory.


2014 ◽  
Vol 556-562 ◽  
pp. 158-161 ◽  
Author(s):  
Xing Guo Feng ◽  
Guang Hui Dong ◽  
Jun Yan Fan

Combining use electrochemical measurement and weight loss testing, the inhibition efficiency of an organic inhibitor was studied in a chloride contaminated solution. The results showed that the added inhibitor can enhance the corrosion potential and decreased the corrosion current density of rebar. The weight loss testing confirmed that the inhibitor reduced the corrosion rate of rebar by 80% in the chloride containing solution. Moreover, the linear polarization results are consistent with the weight loss testing, which suggests that the former is an effective method to estimate the inhibition efficiency of inhibitors.


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