Search

The use of fibres applied to concrete in order to improve its properties is widely known. Nowadays, research is not only focused on improving mechanical properties but also on the environmental implications. The aim of this research was a mechanical and environmental comparison between different types of fibres. For this purpose, commercial fibres of three materials were used: low carbon steel, modified polyolefins, and glass fibre. In order to improve the sustainability of the sector, we also analysed and compared the performance of using a waste product, such as fibres from machining operations on lathes. For the evaluation of the mechanical properties, compression and flexural tests were carried out. The results show that the use of low carbon steel fibres increases the flexural strength by 4.8%. At the environmental level, and in particular for impact categories such as the Global Warming Potential (GWP), lathe waste fibres prove to be the most suitable. For instance, compared to glass fibres, CO2 emissions are reduced by 14.39%. This is equivalent to a total of 38 kg CO2 emissions per m3 of reinforced concrete. In addition to avoiding the consumption of 482 MJ/m3 of fossil fuels, the results of the research indicate the feasibility of using waste fibres as a substitute for commercial fibres, contributing to an improved environmental balance without losing mechanical performance. [ABSTRACT FROM AUTHOR]

The use of glass fiber reinforced concrete (GFRC) in the construction industry is increasing due to its mechanical and physical properties. Waiting time of concrete in the mold and the removal of the mold at the right time are important in terms of strength. In conventional concretes, maturity models are widely used as a non-destructive method for early strength estimate. In this study, it is aimed to develop an estimate model of flexural and compressive strength in GFRCs using the maturity index method. In this context, glass fiber reinforced concretes were produced at the rates of 0%, 1%, 2% and 3%. Calcined kaolin and acrylic polymer were used as modification materials in the mixtures. Properties such as compressive, flexural, hardness, and shrinkage of specimens were investigated at different ages. The maturity-strength relationships of mixtures at different ages were examined by weighted maturity and Nurse-Saul methods. At the end of the study, two new models were developed to estimate the compressive and flexural strengths of GFRCs, taking into account all the data. The suggested models have been confirmed by examining them on all mix-age groups and comparing them with the literature. [ABSTRACT FROM AUTHOR]

Utilization of recycled aggregate from the construction and demolition waste as a partial substitution of natural aggregate in the concrete has been increased in the recent times in order to minimize the consumption of natural resources and the harmful effects to the environment. The present investigation mainly focuses on the influence of different fibers on mechanical and other properties of concrete made with 50% of recycled coarse aggregate (RCA) as well as concrete with 100% natural aggregate. Three types of fibers such as Woolen fibers (WF), Glass fibers (GF), and Steel fibers (SF) were used in both normal and recycled aggregate concrete mixes. The workability, compressive strength, split tensile and flexural strengths, modulus of elasticity, density, water absorption and volume of voids, and ultrasonic pulse velocity (UPV) properties of all the mixes were investigated. From the experimental findings it was observed that the fibers significantly improve the mechanical properties of both normal and recycled aggregate concretes. Further among the WF, GF, and SF, SFs had shown more positive impact on the properties of concrete. [ABSTRACT FROM AUTHOR]

As the progress of using materials for making concrete is growing, a lot of research has been done to make concrete with a variety of materials to get concrete performing well. The compressive strength and split concrete are influenced by what materials are used. This study conducted an experiment to make fibrous concrete using a mixture of fiberglass material type Chopped Strand Mat (CSM), CSM was cut to a size of 1 cm x 4 cm then CSM was described by pulling CSM from the webbing. The cylindrical specimens measuring 150 mm x 300 mm, the compressive strength of the plan 20 Mpa with 4 kinds of mixed variations of 0 %, 0.25 %, 0.5 %, and 0.75 % of the weight of cement used. Compressive and split strength testing of concrete aged 7, 14, and 28 days. The results of slump test results showed that the greater the percentage of Fiberglass the lower the slump produced. The compressive strength test results obtained 0 % at the age of 28 days obtained compressive strength of 20.2 MPa, while the highest addition of fiberglass compressive strength at 28 days the addition of fiberglass by 0.25 % 24.6 MPa. The highest tensile strength at 0.75 % fiber addition was 3.9 MPa, and the maximum flexural strength at 0.75 % fiber addition was 2.889 MPa. From the results of this study it was concluded that with the addition of 0.25 % fiberglass it was found to be strong the highest compressive strength is 24.6 MPa and the splitting strength of 3.9 MPa is produced from the addition of 0.75 % fiber, and the flexural strength of 2.889 MPa is produced from the addition of 0.075 % fiber. with the addition of a certain percentage of fiberglass can add compressive strength, tensile strength and flexural strength in concrete. [ABSTRACT FROM AUTHOR]