In this paper the results of tests performed on specimens and structural elements made of steel fiber reinforced concrete (SFRC) are presented. Fiber content of the concrete ranged from 0 to 60 kg/m³. Using the results of the uniaxial compression tests performed under displacement control condition, a stress-strain relationship for fiber concrete in compression was derived. Three-point bending tests on notched beams were carried out to simulate the postcracking behavior and to evaluate the fracture energy. Based on the constitutive relationships derived from the experiments, a layered model for the analysis of steel fiber reinforced concrete cross sections was developed. The model performance and the benefits of fiber reinforcement on thin slabs reinforced with steel bars were assessed by carrying out tests on slab strips. The main results are presented and discussed.

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Flexural Behavior of SFRC: Testing and Modeling

The strength of steel tubes used in offshore construction is often limited by local and global stability considerations. We propose a new composite tube, which consists of two concentric steel tube...

Performance of New Sandwich Tube under Axial Loading: Experiment

Laboratory and field performance of polymer-modified cement-based repair mortars in cold climates

Polymer concrete was introduced in the late 1950s and became well known in the 1970s for its use in repair, thin overlays and floors, and precast components. Because of its properties like high compressive strength, fast curing, high specific strength, and resistance to chemical attacks polymer concrete has found application in very specialized domains. Simultaneously these materials have been used in machine construction also where the vibration damping property of polymer concrete has been exploited. This review deals with the efforts of various researchers in selection of ingredients, processing parameters, curing conditions, and their effects on the mechanical properties of the resulting material.

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Mechanical Properties of Polymer Concrete

An experimental study to investigate the influence of matrix strength, fibre content and diameter on the compressive behaviour of steel fibre reinforced concrete is presented. Two types of matrix and fibres were tested. Concrete compressive strengths of 35 and 60 MPa, 0·38 and 0·55 mm fibre diameter, and 30 mm fibre length, were considered. The volume of fibre in the concrete was varied up to 1·5%. Test results indicated that the addition of fibres to concrete enhances its toughness and strain at peak stress, but can slightly reduce the Young's modulus. Simple expressions are proposed to estimate the Young's modulus and the strain at peak stress, from the compressive strength results, knowing fibre volume, length and diameter. An analytical model to predict the stress–strain relationship for steel fibre concrete in compression is also proposed. The model results are compared with experimental stress–strain curves.

Compressive behaviour of steel fibre reinforced concrete

The behavior of epoxy and polyester concretes was studied under various curing conditions, temperatures, and strain rates. The influence of aggregate size and distribution on the mechanical properties of polymer concrete (PC) was also investigated. The strain rate was varied between 22 and 120 C (72 and 248 F). The strength, failure strain, modulus, and stress-strain per minute, and the temmperature between 22 and 120 C (72 and 248 F). The strength , failure strain, modulus, and stress-strain relationship of polymer concrete systems are influenced by the curing method, testing temperature, and strain rate to varying degrees. The influence of test variables on the mechanical properties of polymer concrete systems are quantified. Compared to the uniformly graded fine aggregates, the gap-graded aggregates produced polymer concrete with better mechanical properties. The compressive modulus and splitting-tensile strength of polymer concrete are related to their compressive strength. It was found that the property relationsips recommended by ACI codes and others specifically developed for high-strength cement concrete are not directly applicable to the PC systems investigated in this study. A new constitutive model is proposed to predict the complete compressive stress-strain behavior of epoxy and polyester polymer concrete systems. Analytical expressions relating the parameters of the constitutive model to the testing temperature and strain rate are derived.

Performance of epoxy and polyester polymer concrete

Alkali activated materials contain aluminosilicates, which can be used for building with a low environmental impact by repurposing waste resulting in cost-effective construction. The impact of nature and superplasticizer dosage on fly ash slag-based ambient cured mortar activated with sodium silicate and sodium hydroxide is not yet definitive. This paper studies the influence of various superplasticizers on fly ash-based ambient cured mortar activated with sodium silicate and sodium hydroxide. The effect of superplasticizers was evaluated by adding various superplasticizers including melamine, polycarboxylate ether and naphthalene-based superplasticizers in different dosages from 0 – 3% at 0.5% intervals. Fresh properties of alkali-activated mortar with various percentages of superplasticizer were tested using flow table apparatus and compared with mortar without superplasticizer. The hardened property of the alkali-activated mortar was tested by checking the compressive strength of the mortar cube. From the test results, naphthalene and polycarboxylate ether-based superplasticizers are compliant with alkali-activated mortar. Melamine-based superplasticizer shows a slight reduction on strength of alkali-activated mortar. In the ambient cured mortar, the optimum concentration for naphthalene and polycarboxylate ether-based superplasticizers is 2.0 percent, whereas melamine-based superplasticizer exhibits maximum strength for 2.5 percent. Even though naphthalene and polycarboxylate-based superplasticizers are effective for alkali-activated mortar, the most efficient type is the polycarboxylate ether-based superplasticizer. 

Influence of Superplasticizer on Workability and Strength of Ambient Cured Alkali Activated Mortar

2022 Global conference on recent advancements in sustainable materials (GC-RASM 2022) bioactive expolysacharide from marine bacteria microcoocus sp.MRN-01

E. Paul

Papers

Performance of epoxy and polyester polymer concrete

Influence of Superplasticizer on Workability and Strength of Ambient Cured Alkali Activated Mortar

2022 Global conference on recent advancements in sustainable materials (GC-RASM 2022) bioactive expolysacharide from marine bacteria microcoocus sp.MRN-01