scholarly journals Properties of Polymer Modified Concrete in Fresh and Hardened State

2013 ◽  
Vol 687 ◽  
pp. 204-212 ◽  
Author(s):  
Ioana Ion ◽  
José Barroso Aguiar ◽  
Nicolae Angelescu ◽  
Darius Stanciu
Keyword(s):  
Flexural Strength ◽  
Compression Strength ◽  
Rheological Behavior ◽  
Epoxy Resins ◽  
Microstructure Formation ◽  
Cement Ratio ◽  
Strength Tests ◽  
Fresh State ◽  
Hardened State ◽  
Polymer Modified Concrete

It was carried out a study on the properties of polymer modified concrete (PCM) in fresh and hardened state. It was used three types of polymers: epoxy resins, polyurethane and methylcellulose in different percentages and different water cement ratio. The main objectives was to improve workability and rheological behavior of these mixtures in fresh state and mechanical strength tests on hard concrete. Has been investigated the polymer influence on compression strength and flexural strength and analyzing the time evolution of these strengths and participation of polymer in the microstructure formation.

scholarly journals Importance of rheology in the prediction of structural transition phenomena in geopolymer matrices loaded with phosphogypsum

2019 ◽  
Vol 286 ◽  
pp. 07005
Author(s):  
N. Lahlou ◽  
M. Ouazzani Touhami ◽  
R. Hattaf ◽  
R. Moussa
Keyword(s):  
Rheological Behavior ◽  
Structural Transition ◽  
Experimental Approach ◽  
Fresh State ◽  
Hardened State ◽  
Definition Of ◽  
The Impact ◽  
Kinetics Of

Through a purely experimental approach, we proceed here to the description of the rheological behavior of the geopolymer matrices in the fresh state according to one or other of the parameters characterizing their formulation. This consolidates the different physicochemical techniques usually used for their characterization. This comes to allow us especially the definition of drafts for the implementation of empirical laws ensuring a better follow-up in the elaboration of these materials or even more optimization in their formulation. This description also allows us to follow the structural transition phenomena from the fresh state to the hardened state. We are particularly interested in demonstrating the impact of the addition of Phosphogypsum on the rheological behavior of geopolymers or on their kinetics of setting.

Characterization of a self-compacting sand concrete using the quarry waste

2009 ◽  
Vol 36 (11) ◽  
pp. 1773-1782 ◽  
Author(s):  
A. Abidelah ◽  
A. Bouchaïr ◽  
D. Kerdal ◽  
K. Ayed
Keyword(s):  
Mechanical Behavior ◽  
Rheological Behavior ◽  
Environmental Problem ◽  
Mechanical Performance ◽  
Maximum Size ◽  
Water Volume ◽  
Volume Weight ◽  
Fresh State ◽  
Hardened State

Self-compacting sand concrete (SCSC) can be made by using the quarry waste, thus helping to reduce the actual deficit in aggregates in Algeria and contribute to the solution of an acute environmental problem. The SCSC presented in this paper is made with aggregates whose maximum size is less than 5 mm. Several mixes were prepared by varying parameters, such as water volume, weight and nature of cement, weight of sand, nature of admixtures, and shape of aggregates. Each one of the SCSC mixes has been analyzed by considering its rheological behavior in the fresh state and its mechanical behavior in the hardened state. In the fresh state, the elaborated SCSC satisfies the recommendations of the Association Française de Génie Civil (AFGC) and in the hardened state, its mechanical performance is good.

Mechanical Properties Evaluation of Render Mortars with Different Waterproof Additive Compositions

2021 ◽  
Vol 880 ◽  
pp. 161-167
Author(s):  
Joaquin Humberto Aquino Rocha ◽  
Fernando Palacios Galarza
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Flexural Strength ◽  
Direct Effect ◽  
Compression Strength ◽  
Negative Impact ◽  
Experimental Tests ◽  
Strength Tests ◽  
Different Types ◽  
The Common

Waterproof additives and bonding agent mixtures are commonly employed in the setting up of render mortars. This practice often shows beneficial results, enhancing the properties of the common mortars. Yet, the use of these additives does not seem to have a direct effect on the mechanical properties of the mortars. This study thus aims to evaluate the influence of the use of waterproof and adhesion additives on the mechanical properties of render mortars. Based on their chemical composition, three different types of mortar admixtures were evaluated, using fourfold additive-mortar weight ratios: 0%, 1.5%, 3%, and 5%. Compressive and flexural strength tests were conducted after 28 days. The results showed a negative impact on the mechanical properties of the mortars. The lowest flexural and compression strength values reported are 1.52 and 4.57 (MPa), respectively. However, all compressive and flexural strength values lied within the limit range recommended by the “Mortars applied on walls and ceilings” construction code (i.e., ABNT NBR 13281). It is compulsory to continue the experimental tests to determine render mortars mechanical properties with higher waterproof additive-mortar weight ratios since higher ratios might produce mortars with non-allowed mechanical properties.

Properties and Behavior of Starch Biopolymer Concrete

2020 ◽  
Vol 38 (10A) ◽  
pp. 1414-1420
Author(s):  
Waleed A. Abbas ◽  
Hawraa M. Mohsen
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Corn Starch ◽  
Splitting Tensile Strength ◽  
Natural Polymer ◽  
Mix Proportion ◽  
Fresh State ◽  
Hardened State ◽  
And Behavior

Starch act as natural polymer has been got from Wheat, Tapioca, and Corn. Corn starch has been investigated as biopolymer and has been added to concrete in different percentages (0%, 0.5%, 1%, and 1.5%) by cement weight and the study shows the effect of using starch on some properties of concrete in the fresh state ( slum and fresh density) and at hardened state (compressive strength, splitting tensile strength and flexural strength) at 28 days. The mix proportion was(1:2.3:2.3) (cement: sand: gravel) respectively and at constant w/c equal to 0.47.The results indicate that the optimum percentage of starch addition was 0.5%, so it showed an increase by 50%in compressive strength and splitting tensile strength; while, the increases in flexural strength were 26%. Slump showed a 25% increase and fresh density showed a 2.5% increase at 0.5% addition of starch.

scholarly journals Printing Parameter Requirements for 3D Printable Geopolymer Materials Prepared from Industrial Side Streams

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4758
Author(s):  
Qaisar Munir ◽  
Riku Peltonen ◽  
Timo Kärki
Keyword(s):  
Flexural Strength ◽  
Raw Materials ◽  
Setting Time ◽  
Shape Stability ◽  
Strength Tests ◽  
Material Heating ◽  
Hardened State ◽  
Traditional Manufacturing ◽  
Increased Strength ◽  
Printing Parameter

The objective of this investigation is to study the printing parameter requirements for sustainable 3D printable geopolymer materials. Side streams of the paper, mining, and construction industries were applied as geopolymer raw materials. The effect of printing parameters in terms of buildability, mixability, extrudability, curing, Al-to-Si ratio, and waste materials utilisation on the fresh and hardened state of the materials was studied. The material performance of a fresh geopolymer was measured using setting time and shape stability tests. Standardised test techniques were applied in the testing of the hardened material properties of compressive and flexural strength. The majority of developed suitable 3D printable geopolymers comprised 56–58% recycled material. Heating was used to improve the buildability and setting of the material significantly. A reactive recyclable material content of greater than 20% caused the strength and material workability to decrease. A curing time of 7–28 days increased the compressive strength but decreased the flexural strength. The layers in the test samples exhibited decreased and increased strength, respectively, in compressive and flexural strength tests. Geopolymer development was found to be a compromise between different strength values and recyclable material contents. By focusing on specialised and complex-shape products, 3D printing of geopolymers can compete with traditional manufacturing in limited markets.

A Study on Influence of Shape of Aggregate on Strength and Quality of Concrete for Buildings and Pavements

2014 ◽  
Vol 941-944 ◽  
pp. 776-779 ◽  
Author(s):  
Kumar Molugaram ◽  
Jaya S. Shanker ◽  
Adepu Ramesh
Keyword(s):  
Flexural Strength ◽  
Vital Role ◽  
Hardened Concrete ◽  
Cement Concrete ◽  
Strength Tests ◽  
Hardened State ◽  
Different Shapes ◽  
And Performance ◽  
The Cost

Aggregate characteristics of shape, texture and grading influence on workability, finishability, bleeding, pumpability and segregation of fresh concrete and affects the strength, shrinkage, density, and durability of hardened concrete. About 80% of total volume of concrete consists of aggregate. Construction and durability problems have been reported due to poor mixture proportioning and variation on grading. Aggregate characteristics significantly affect the performance of Quality Concrete (QC) both in fresh and hardened state and have an impact on the cost effectiveness. Flaky and elongated particles lead to higher voids than cubical, rounded and well graded particles. The shape factor of aggregate plays a vital role in the design and performance of QC mix and it is mainly depends on the rock formation and type of crusher being used for crushing the aggregates. Flaky and elongated particles have larger specific surface area which results in higher demand of cement paste in cement concrete mix. These particles impede compaction or break during rolling and decrease the strength of the concrete structures. An attempt is made to study the effect of shape of aggregate on quality of the concrete used for the buildings and pavements. Initially an aggregate samples were collected from the stone crusher (two types) and prepared with different proportions of Flakiness and Elongation indices to conduct tests on properties of aggregates and compressive strength and flexural strength tests on concrete. The effect of different percentages from 0 to 50% of combined Flaky and Elongation Aggregates (CFEA) for quality concrete on the compressive and flexural strength of cement concrete is studied. The other properties of aggregate such as bulk density, impact value, water absorption have been studied for different shapes of aggregates. The cost analysis has been carried out with an optimum value of 30% CFEA in 1:3 proportions of flaky and elongated particles.

scholarly journals Investigation on the Mechanical Properties and Post-Cracking Behavior of Polyolefin Fiber Reinforced Concrete

Fibers ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 8
Author(s):  
Suman Adhikary ◽  
Zymantas Rudzionis ◽  
Arvind Balakrishnan ◽  
Vignesh Jayakumar
Keyword(s):  
Flexural Strength ◽  
Mouth Opening ◽  
Strength Properties ◽  
Fiber Reinforced Concrete ◽  
Concrete Mixture ◽  
Partial Replacement ◽  
Crack Mouth Opening Displacement ◽  
Cracking Behavior ◽  
Strength Tests ◽  
Fresh State

This paper deals with the behavior of concrete’s self-compatibility in a fresh state and its compressive and flexural strength in a hardened state with the addition of polyolefin macro fibers. Four different amounts (3 kg/m3, 4.5 kg/m3, 6 kg/m3, and 9 kg/m3) of polyolefin macro fibers were mixed into the concrete mixture to observe the differences in workability and strength properties between the concrete specimens. As a partial replacement of cement, class C type of fly ash was added to make up 25% of the total cement mass. The water-binder ratio (W/B) of the concrete mix was 0.36. Superplasticizer was added to the concrete mixture to achieve self-compacting properties. The slump test was carried out in the fresh state for determining the flowability. On the 7th and 28th days of the curing process, compression strength tests were performed, and on the 28th day, flexural strength tests and crack mouth opening displacement (CMOD) analyses were carried out to determine the strength properties and post-cracking behavior of the concrete samples. Bending strength and post-cracking behavior of the samples were improved by the addition of fibers. The fiber concentration in the concrete mixture greatly influenced the slump flow and self-compaction properties.

Some Mechanical Properties of Polymer Modified Concrete by Adding Waste Iron Filings and Chips

2021 ◽  
Vol 895 ◽  
pp. 110-120
Author(s):  
Marwah Jaafar Kashkool ◽  
Wisam Abdulilah Almadi ◽  
Qusay A. Jabal ◽  
Layth Abdul Rasool Al Asadi ◽  
Jaber Kadhim Alghurabi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Polymer Concrete ◽  
Fine Aggregate ◽  
Cement Ratio ◽  
Super Plasticizer ◽  
Polymer Modified Concrete

The study aims to improve some mechanical properties like compressive strength, tensile strength, modulus of elasticity and flexural strength of polymer modified concrete (PMC). This improving for PMC done by using waste iron filling as replacement from fine aggregate. waste iron filings and chips used in this research as percentages from sand ranged from 0 % to 40 % , the compressive strength of ordinary polymer concrete increase from 32.2 MPa to 41.81 MPa by 40% replacement of sand with waste iron filings and chips, tensile strength increased also from 2.83 MPa to 4.23 MPa by 40% replacement also. Flexural strength increased from 3.7 MPa for reference mix to about 7.1 MPa for mixes with 40% replacement, modulus of elasticity increased from 21087 MPa to 25233 MPa by using maximum percentage of waste iron filings. There is a slight increment in mechanical properties of polymer modified concrete after 30% ratio of waste iron filings and chips. Also research includes mixes modified with larger dosage of super plasticizer and less water/cement ratio to improve mechanical properties of PMC.

scholarly journals Use of recycled aggregates from civil construction in self-compacting mortar

2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Fernanda Rodrigues Santos Valle ◽  
Paulo Cesar Gonçalves ◽  
Maria Gabriela A. Ranieri ◽  
Mirian de Lourdes Noronha Motta Melo ◽  
Valquíria Claret dos Santos
Keyword(s):  
Raw Materials ◽  
Significant Loss ◽  
Recycled Aggregates ◽  
Self Compacting Concrete ◽  
Financial Cost ◽  
Flexural Tensile Strength ◽  
Strength Tests ◽  
Fresh State ◽  
Hardened State ◽  
Interesting Alternative

abstract: The utilization of wastes from demolition in civil construction in self compacting concrete (SCM) has the potential to reduce both the environmental impact and financial cost. In this context, this article aims to verify the behavior of the incorporation of recycled aggregates of civil construction in the mix designs of self-compacting mortar (SCM) in replacing cement, presenting as an interesting alternative to natural raw materials. This study used the EMMA® software to optimize the choice of percentages of fine recycled aggregates when replacing cement. The proportions chosen were 0%, 5%, 15%, and 25%, through the analysis of the granular packing curve of the respective mix designs. The proportion of 0% has in its composition cement, metakaolin, sand, superplasticizer (SP) and water. The parameters obtained, through tests in the fresh state of the mini-slump and mini-funnel V, certified the samples as SCM. The compressive strength and flexural tensile strength tests in the hardened state demonstrated a reduction in mechanical properties of the material with cement replacement. It is concluded that the waste used brick and ceramic can be added in replacement to the cement in SCM without significant loss of properties in the fresh and hardened state.

scholarly journals Study of cement pastes rheological behavior using dynamic shear rheometer

2014 ◽  
Vol 7 (6) ◽  
pp. 922-939
Author(s):  
J. E. S. L. Teixeira ◽  
V. Y. Sato ◽  
L. G. Azolin ◽  
F. A. Tristão ◽  
G. L. Vieira ◽  
...  
Keyword(s):  
Rheological Behavior ◽  
Scientific Community ◽  
Flow Characteristics ◽  
Bingham Fluid ◽  
Material Behavior ◽  
Rheological Parameters ◽  
Cement Pastes ◽  
Cement Ratio ◽  
Flow Test ◽  
Fresh State

Concrete, in its fresh state, has flow characteristics that are crucial to its proper launch and densification. These characteristics are usually measured through empirical testing as the slump test, but this test does not quantify completely the material behavior. Since this material is characterized as a Bingham fluid, it is essential the study of its rheological behavior to verify its properties even in fresh state. The use of classical rheology has been employed by the scientific community to obtain rheological parameters determinants to characterize this material, such as yield stress, plastic viscosity and evolution of shear stress to shear rate. Thus, this present study aims to determine the rheological behavior of different cement pastes produced with cement CP III 40 RS, varying between them the hydration periods (20 and 60 min), the water-cement ratio (0.40, 0.45 and 0.50) and the use or not of additive. Samples were assayed by flow test to determine the rheological parameters showing the effect of the variables mentioned above in these parameters.

Sign in / Sign up

Export Citation Format

Share Document