Capillary suction induced water absorption and chloride transport in non-saturated concrete: The influence of humidity, mineral admixtures and sulfate ions

2020 ◽  
Vol 236 ◽  
pp. 117581 ◽  
Author(s):  
Chang Honglei ◽  
Jin Zuquan ◽  
Zhao Tiejun ◽  
Wang Benzhen ◽  
Li Zhe ◽  
...  
Keyword(s):  
Water Absorption ◽  
Chloride Transport ◽  
Mineral Admixtures ◽  
Capillary Suction ◽  
Sulfate Ions ◽  
Saturated Concrete

scholarly journals Preliminary Study of the Targeted Cleaning of an Artificial Gypsum Layer on White Marble

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
Yan Liu ◽  
Taoling Dong ◽  
Kun Zhang ◽  
Fuwei Yang ◽  
Liqin Wang
Keyword(s):  
Electron Microscopy ◽  
Barium Carbonate ◽  
Color Difference ◽  
X Ray Diffraction ◽  
White Marble ◽  
Capillary Suction ◽  
Sulfate Ions ◽  
X Ray ◽  
Preliminary Study ◽  
Scanning Electron

Targeting cleaning of the artificial gypsum layer on white marble was studied. It was conducted by means of the specific depletion of the calcium and sulfate ions by the barium carbonate scavenger, which led to the continuous dissolution and clearance of gypsum layer. The cleaning effect was evaluated by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), X-ray diffraction (XRD), capillary suction, and color difference measurement. By this method, only the gypsum layer was cleared away and the carbonate substrate of marble was left intact at the same time. This method will be highly useful for the conservation of marble relics from surface weathering.

Modelling of chloride transport in non-saturated concrete

2014 ◽  
pp. 781-788 ◽  
Author(s):  
M Fenaux ◽  
J Gálvez ◽  
E Reyes ◽  
A Moragues ◽  
J Bernal
Keyword(s):  
Chloride Transport ◽  
Saturated Concrete

scholarly journals Biofuel Combustion Fly Ash Influence on the Properties of Concrete

2016 ◽  
Vol 7 (5) ◽  
pp. 546-550
Author(s):  
Aurelijus Daugėla ◽  
Džigita Nagrockienė ◽  
Laurynas Zarauskas
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Water Absorption ◽  
Frost Resistance ◽  
Ash Content ◽  
Mineral Admixtures ◽  
Binding Agent ◽  
Materials Used ◽  
Plasticizing Admixture

Cement as the binding agent in the production of concrete can be replaced with active mineral admixtures. Biofuel combustion fly ash is one of such admixtures. Materials used for the study: Portland cement CEM I 42.5 R, sand of 0/4 fraction, gravel of 4/16 fraction, biofuel fly ash, superplasticizer, water. Six compositions of concrete were designed by replacing 0%, 5%, 10%, 15% 20%, and 25% of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the properties of concrete. The tests revealed that the increase of biofuel fly ash content up to 20% increases concrete density and compressive strength after 7 and 28 days of curing and decreases water absorption, with corrected water content by using plasticizing admixture. It was found that concrete where 20% of cement is replaced by biofuel ash has higher frost resistance.

scholarly journals Metakaolin Influence on Concrete Durability Properties

2019 ◽  
Vol 8 (11) ◽  
pp. 1109-1111
Keyword(s):  
Water Absorption ◽  
Mineral Admixture ◽  
Engineering Properties ◽  
Mineral Admixtures ◽  
Concrete Durability ◽  
Acid Attack ◽  
Initial Water ◽  
Durability Properties ◽  
Weight Losses ◽  
Permanence Properties

Mineral admixtures are being used today almost in all concretes partially, to improve workability, engineering properties and also to enhance durability of the concrete. These admixtures are industrial by-products. In the present study, mineral admixture such as metakaolin (MK) is replaced partially in cement to investigate permanence properties of concrete in terms of initial water absorption, final water absorption and confrontation to acid attack. Inorder to identify the durability properties, concrete of M30 grade was prepared. The mineral admixture content was varied from 0% to 30% by volume of cement with 10% gradient. In acid attack, 3% H2SO4 solution is used for curing of specimens and the corresponding weight losses (%) were evaluated for curing periods of 7 days, 14 days and 28 days. Both initial and final water absorptions of the metakaolin-modified concrete have been improved when metakaolin content was increased up to 10% advantageously. And, also weight loss was decreased when metakaolin content varied from 0% to 30%.

scholarly journals Effect of PFA on Strength and Water Absorption of Mortar

2011 ◽  
Vol 2 (1) ◽  
pp. 7-11
Author(s):  
Gingos G.S. ◽  
Mohamed Sutan N.
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Strength Development ◽  
Laboratory Studies ◽  
Fuel Ash ◽  
Pulverized Fuel ◽  
Pulverized Fuel Ash ◽  
Reduced Rate

Partial replacement of cement by mineral admixtures or pozzolans can possibly improve the durability of mortar which directly related to its water absorption. Pulverized Fuel Ash (PFA) is one of the pozzolans that is locally available. Laboratory studies have been conducted on mortar mixes of 0.3w/c, 0.4w/c and 0.5w/c ratios with 10%, 20% and 30% PFA replacements. Mortar cubes were tested to determine their water absorption rates and compressive strengths as they mature. Amount of PFA replacements in the mortar has significant effects on the strength development and water absorption rate of the mortar. Results shows that 20% PFA mortars of 0.5w/c ratio is the best mix to reduced rate of water absorption and achieved higher compressive strength.

scholarly journals Capillary Water Absorption and Micro Pore Connectivity of Concrete with Fractal Analysis

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 892
Author(s):  
Xiangqun Ding ◽  
Xinyu Liang ◽  
Yichao Zhang ◽  
Yanfeng Fang ◽  
Jinghai Zhou ◽  
...  
Keyword(s):  
Pore Structure ◽  
Water Absorption ◽  
Fractal Theory ◽  
Mineral Admixtures ◽  
Capillary Water ◽  
Capillary Water Absorption ◽  
Connectivity Probability ◽  
Fractal Characteristics ◽  
Different Diameters ◽  
The Relationship

This study focuses on the relationship between the complexity of pore structure and capillary water absorption of concrete, as well as the connection behavior of concrete in specific directions. In this paper, the water absorption of concrete with different binders was tested during the curing process, and the pore structure of concrete was investigated by mercury intrusion porosimetry (MIP). The results show that the water absorption of concrete with mineral admixtures is lower, mainly due to the existence of reasonable pore structure. The effect of slag on concrete modification is more remarkable comparing with fly ash. In addition, the analysis shows that the pore with different diameters has different fractal characteristics. The connectivity probability and water absorption of unidirectional chaotic pore are linearly correlated with the pore diameter of 50–550 nm, and the correlation coefficient reaches a very significant level, and detailed analysis was undertaken to interpret these results based on fractal theory.

scholarly journals Utilization of Agroresidual Waste in Effective Blending in Portland Cement

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
A. K. Parande ◽  
Karthick Stalin ◽  
Ravi Kumar Thangarajan ◽  
M. S. Karthikeyan
Keyword(s):  
Portland Cement ◽  
Water Absorption ◽  
Agricultural Waste ◽  
Dry Weight ◽  
Mineral Admixtures ◽  
Replacement Level ◽  
Pozzolanic Reactivity ◽  
Effective Level ◽  
Bulk Volume ◽  
Artificial Mineral

Indigenous resources for natural and artificial mineral admixtures with high pozzolanic reactivity have been employed in many countries around the world. Extensive studies have been conducted for this purpose. With the use of agricultural waste residue, apart from improving properties of concrete, main benefits come from saving natural resources and energy, as well as protecting the environment by using these mineral admixtures (agroagricultural waste). The effective level of blending Portland cement (PC) in mortar or concrete with such mineral admixtures depends on many factors, such as the type of admixture and the cement replacement level. In the present paper two types of agroagricultural waste residue, namely, rice husk ash, bagasse ash and byproduct from thermal waste and fly ash were used. The above mentioned admixtures were thermally treated at a temperature of 650∘C. Characterizations of mineral admixtures were carried out by FTIR and XRD, and Microstructural properties were evaluated in concrete and mortar with partially replacement levels varying from 5% to 30%. Various tests such as water absorption, bulk volume of the specimen, dry weight of the specimen saturated mass, and coefficient of water absorption were concluded. The results showed that as the percentage of replacement level increases in the entire three admixtures studied, water absorption also increased.

scholarly journals Chloride transport on partially saturated Concrete media: the influence of the hydric state

2017 ◽  
Vol 139 ◽  
pp. 367-372
Author(s):  
Hayet Chalabi ◽  
Abdelillah Bezzar ◽  
Abdelhafid Khelidj
Keyword(s):  
Chloride Transport ◽  
Partially Saturated ◽  
Saturated Concrete

Evaluation of Incorporation of Dregs in Mortar Production in Replacement of Hydrated Lime

2016 ◽  
Vol 881 ◽  
pp. 351-356
Author(s):  
Rodrigo Felipe Santos ◽  
Rita de Cássia Silva Sant’Ana Alvarenga ◽  
Beatryz Cardoso Mendes ◽  
José Maria Franco de Carvalho ◽  
Leonardo Gonçalves Pedroti
Keyword(s):  
Experimental Design ◽  
Absorption Coefficient ◽  
Water Absorption ◽  
Hydrated Lime ◽  
Quadratic Model ◽  
Lattice Method ◽  
Water Absorption Coefficient ◽  
Capillary Suction ◽  
Model Adjustment ◽  
Simplex Lattice

The dregs is a residue from the cellulose production, and finding new ways to use it would be interesting to reduce environmental impacts. This study aimed at incorporating it into mortar mixture ratios to replace the hydrated lime. Different proportions of cement, sand and dregs were evaluated using the Simplex-Lattice method of experimental design, and it was analyzed water absorption coefficient, compressive strength and flexural strength. The model adjustment was made with seven points plus three axial points and in terms of pseudo-components. A linear model was adjusted for the first characteristic, and a quadratic model for the second and third characteristics. Larger rates of capillary suction and smaller resistance values were noticed with a larger amount of dregs. This experimental design proved feasible, allowing the obtainment of mixture ratios from pre-determined values of water absorption coefficient and resistance, and making more objective the addition of dregs to mortar mixtures.

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