scholarly journals Mechanical strength and hydraulic properties of modified porous concrete mixtures

2021 ◽  
Vol 1895 (1) ◽  
pp. 012027
Author(s):  
Hussein J. Almansori ◽  
Adnan Al-Sibahy ◽  
Basim Al-Humeidawi
2020 ◽  
Vol 12 (6) ◽  
pp. 2392 ◽  
Author(s):  
Eduardo-Javier Elizondo-Martínez ◽  
Valerio-Carlos Andrés-Valeri ◽  
Jorge Rodríguez-Hernández ◽  
Cesare Sangiorgi

Despite the number of environmental advantages that porous concrete (PC) pavements can provide, they are mainly used in light-traffic roads, parking lots and sidewalks due to their low mechanical strength. This research focuses on the common additives employed in PC pavements, according to a literature review, with the aim of increasing their mechanical strength while maintaining an acceptable infiltration capacity. The results demonstrated that the combination of superplasticizers and air-entraining additives can provide indirect tensile strength values over 2.50 MPa, with an infiltration capacity over 0.40 cm/s. In addition, polypropylene fibers were seen to provide very good safety properties, preserving some structural integrity in the case of failure. All mixtures studied obtained outstanding skid resistance results under both dry and wet conditions.


2021 ◽  
Vol 27 (1) ◽  
pp. 135-142
Author(s):  
Wira Rante Paganggi ◽  
Amelia Makmur ◽  
Rachmansyah Rachmansyah

The infrastructure growth has an impact on reducing green areas, which will be followed by reduced water catchment areas. Porous concrete is one of the porous materials that can be used on a pedestrian walk, which is able to drain water. The porous concrete has a limitation strength. This research aims to determine the effect of using various content of chemical additive and polypropylene fibers for porous concrete mixtures related to the compressive strength and permeability values. This experimental method referring to ACI 522R-10 Standard. That specimens using chemical additives and variations of polypropylene fibers: 0.05%, 0.1%, 0.15%, 0.2%, and 0.25% by weight of cement. The results showed that the specimen which had the highest compressive strength was 16.9 MPa, which was added 0.25% polypropylene fiber. The addition of polypropylene fibers increases the compressive strength value by 5.6%. Based on the compressive strength and permeability graphs, it can be estimated that the optimal content of polypropylene fiber is 0.17% by weight of cement.


2021 ◽  
Vol 13 (19) ◽  
pp. 10562
Author(s):  
Carlos Sánchez-Mendieta ◽  
Juan Jose Galán ◽  
Isabel Martinez-Lage

The work presented includes a review of the state of art of porous concrete. Its purpose is to evaluate the potential use of porous concrete in constructions where the level of surface runoff justifies it. A review of the literature presented here has been necessary where parameters of special consideration have been defined in the dosage of permeable mixtures. The study includes the definition of porous concrete in terms of its main components: cement, coarse aggregate, water, additives, and sand, in little or no quantity, to cause the generation of an effective content of interconnected voids that allow rapid storm drainage. Given the reports of variables of high incidence in the mechanical behavior of porous concrete (resistance/permeability relationship), an investigation is warranted to synthesize the effects of the variables in the preparation of the mixture: water–cement ratio, granulometry, and morphology of the aggregates, compaction pressure, and curing techniques, among others. Likewise, the protocols for the characterization of porous concrete and additional aspects relevant to support the experimental phase are exposed, constituting a reference or anchor point for developing technologies associated with the manufacture of this material and the possibilities of its implementation in constructions.


Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3100 ◽  
Author(s):  
Eduardo Javier Elizondo-Martinez ◽  
Valerio Carlos Andres-Valeri ◽  
Jorge Rodriguez-Hernandez ◽  
Daniel Castro-Fresno

Although porous concrete pavement design methods are mainly focused on maintaining high permeability rates in order to improve their ability to manage stormwater runoff, the mixture strength is paramount for its durability and service life. This paper proposes a new mixture design method for porous concrete, named PCD (porous concrete design), derived from the ACI 522R-10 and ACI 211.3R-02 standards. The aim is to improve mechanical strength in porous concrete mixtures, while ensuring enough permeability for its use in urban roads. With PCD methodology it is possible to obtain mechanical strengths 30% higher than those produced with ACI methodologies, while maintaining permeability rates close to 2 cm/s, lower than those obtained with ACI methods but still enough to manage extreme storm events. Finally, with the analytical Hierarchy Process (AHP) multi-criteria decision-making methodology and also bearing in mind safety variables, the best porous concrete mixtures are the ones produced with PCD methodology.


2020 ◽  
Vol 12 (10) ◽  
pp. 4243 ◽  
Author(s):  
Eduardo-Javier Elizondo-Martinez ◽  
Piergiorgio Tataranni ◽  
Jorge Rodriguez-Hernandez ◽  
Daniel Castro-Fresno

Alternative materials to replace cement in pavements have recently been widely studied with the purpose of decreasing the environmental impacts that the construction industry generates. In this context, the implementation of sustainable urban drainage systems has grown, especially with porous pavements, with the intention to reduce water and environmental impacts. In the present investigation, the addition of alternative materials to minimize the use of cement in porous concrete pavements is evaluated. Starting from a partial substitution of Portland cement with metakaolin, experimental geopolymer concretes were produced with metakaolin and waste basalt powder according to several dosages. Two sets of mixtures were analyzed to evaluate the Porous Concrete Design (PCD) methodology for porous concrete mixtures with alternative materials. A deep analysis was proposed for the evaluation of the mechanical and volumetric properties of the mixtures. Results demonstrated that replacing 5% of cement with metakaolin can increase both permeability and indirect tensile strength. Geopolymer mixtures can achieve permeability significantly higher than the traditional porous concrete, but this decreases their indirect tensile strength. However, considering the promising results, an adjustment in the mix design of the geopolymer mixtures could increase their mechanical properties without negatively affecting the porosity, making these materials a suitable alternative to traditional porous cement concrete, and a solution to be used in urban pavements.


2017 ◽  
Vol 8 (3) ◽  
pp. 3-7
Author(s):  
Paweł Ogrodnik ◽  
Bartosz Zegardło

This work is a continuation of the authors' research conducted to develop innovative concrete mixtures containing recycled ceramic aggregates formed after crushing of waste ceramic sanitary elements. The article presents the problem of utilization of ceramic waste, there are listed factors of waste generating and the main characteristics of the waste material. Based on available literature, there are presented the results of research work on successfully using ceramic waste aggregates in the production of concrete composites. The main aim of this work was to design innovative concrete containing sanitary waste which would be permeable to water. The composite presented in the work showed total water permeability. The tested strength parameters allowed us to propose using it for the communication substrates carrying the load from pedestrian traffic. In this type of communication substrates the authors see a remedy for the problem of utilizing rainwater. Especially in urban areas where is no rain water sewer system this solution would have a legitimate benefit. Totally permeable communication routes could directly transfer water to the substrate under their surface which would effectively increase the chance of natural rainwater absorption.


1999 ◽  
Vol 5 (3) ◽  
pp. 217-221
Author(s):  
Loreta Kazragis ◽  
Halina Valaitytė

Concrete and reinforced concrete construction of buildings and bridges, concrete slabs for laying streets, concrete tiles for laying pavements and squares are often covered with thin coating reminding of stalactites or white-grey flows. This phenomenon can be called stalactitization of concrete. It does not just worsen the decorative properties of concrete and reinforced concrete, but also weakens the mechanical strength of these materials. We discuss the reasons of stalactitization of concrete and reinforced concrete constructions and articles and recommend means to weaken this process. The processes of concrete structure stalactitization and formation of thin coating can be delayed in the following ways: Using a filler in production, which has calcite and limestone as little as possible, and controlling their amount by methods of chemical analysis. For CaO (0,5%), present in Portland cement, and for forming Ca(OH)2 in concrete neutralization substances containing SiO2 and SiO2 nH2O can be used but, to prevent alkaline corrosion of concrete, they can be applied only when Portland cement contains very little Na2O and K2O. If there is a possibility, do not use passivated Portland cement containing FeSO4 and A1(SO4)3. Avoid an excess of water when making concrete mixtures. Coloured or other concrete articles should be stored under a roof or at least be covered.


Author(s):  
Shark M. Rakhimbaev ◽  
◽  
Tatiana V. Anikanova ◽  
Anastasia V. Prokopishina ◽  
Alexey S. Pogromskiy ◽  
...  

The study showed that in order to accelerate the hydration of inorganic binders it is necessary to use additives of such electrolytes that increase the concentration of calcium ions in the liquid phase of the cement suspension. Electrolytes (soda ash, sodium and potassium hydroxides), precipitating calcium ions in the liquid phase, promote their exit from the "shut-off" layer of hydration products. In this paper, we studied the additives – electrolytes – as regulators of the setting time of fine-grained and porous concrete. To increase the activity of the additive as a concrete mixtures setting time regulator, acidic varieties were used instead of main salts. The studied additives – electrolytes – draw practical interest, as their usage in production of foam concrete and fine-grained concrete lets accelerate hardening of products and speed up reuse of mould.


Pervious or Porous concrete pavements are an alternative to rigid conventional concrete pavement surfaces. The main purpose of pervious pavements is to reduce the stagnation of rain water on the surface during rainy season by permitting the storm water percolate downwards into the ground. It is obtained by completely or partially eliminating the fine aggregates in the mixture proportions. In this work, effort has been taken to develop pervious concrete mixtures with different void contents and evaluating its mechanical properties at 28 days. From the experimental investigations performed, it was found that mix P1 with 15% void content has attained a maximum strength of 15 MPa. It was also observed from this study that the properties of pervious concrete mainly depend on the void content of the concrete mixtures.


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