Overview of “Recommendation for Mix Design of Fresh Concrete and Construction Placement related Performance Evaluation─2016” published by JSCE

2016 ◽  
Vol 54 (10) ◽  
pp. 987-992
Author(s):  
S. Urano ◽  
S. Hashimoto ◽  
C. Hashimoto ◽  
T. Ayano
Author(s):  
N. SATHEESHKANNA

Waste generated from industries and from various places around us not only contains rubber or plastics but contains lot many harmful pollutants whichare hazardous if disposed continuously in open and leftto degrade in our environment.Our project aims to study properties of different materials which may help in utilising the waste as well as improve the quality of roads and make them efficient, stable, durable and long lasting. Some of the materials that we have studied and considered to be tested in the partial replacement of bitumen are PMB and CRMB.


2018 ◽  
Vol 149 ◽  
pp. 01054
Author(s):  
Nadia Tebbal ◽  
Zine El Abidine Rahmouni ◽  
Lamis Rabiaa Chadi

The objective of this study is to analyze the effect of the air entrainment on the fresh rheological properties as well as on the compressive mechanical resistances of the mortars. The hardened concrete contains a certain amount of randomly spread air, coming either from a drive during kneading or from the evaporation of the mixing water. The air quantity is in the order of 20 l / m3, ie 2% of the volume. However, the presence of a large volume of air bubbles causes the mechanical resistances to fall in compression. On the other hand, the use of air entrainment could improve the rheological properties of fresh concrete. Experimental studies have been carried out to study the effect of air entrainment on compressive strength, density and ingredients of fresh concrete mix. During all the study, water cement ratio (w/c) was maintained constant at 0.5. The results have shown substantial decreasing in water and mortar density followed with decreasing in compressive strength of mortar. The results of this study has given more promising to use it as a guide for mortar mix design to choose the most appropriate concrete mix design economically.


2019 ◽  
Vol 1 (2) ◽  
pp. 124-132
Author(s):  
Hermansyah ◽  
Moh Ihsan Sibgotuloh

The more widespread use of concrete construction and the increasing scale of construction, the higher the demand for materials used in concrete mixes. One of the innovations of concrete is fiber concrete. Hope the addition of fiber in concrete mixes such as wire fiber to increase the compressive strength value of normal concrete that is often used, so the purpose of this study is to determine the effect of adding wire fiber to the ease of working (workability) of the concrete mixture and to determine the effect of adding wire fiber to concrete compressive strength. In this study, the fiber used is the type of wire fiber with a diameter of 1 mm and a length of 60 mm. Fiber variations used are 0%, 0.4%, 0.6% and 0.8% based on the weight of fresh concrete. Concrete mix (mix design) using SNI 03-2834-2000 about concrete mix planning with a test life of 28 days. The test results showed that the lowest average compressive strength of 12,291 MPa occurred at 0% variation and the highest average compressive strength value of 20,656 MPa at 0.8% fiber variation. The increase is caused by the even distribution of fibers in the concrete produced, the higher the variation that is given by the fiber, the better the fiber spread, from these fibers provide a fairly good contribution to the fiber concrete


Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7406
Author(s):  
Matthias Kalthoff ◽  
Michael Raupach ◽  
Thomas Matschei

A promising process for the automatization of concrete structures is extrusion or extrusion molding. An innovative approach is the extrusion of concrete with imbedded technical textiles as reinforcement. For a successful extrusion, the rheological properties of the fresh concrete have to be optimized, as it must be extrudable and have sufficient early strength after leaving the mouthpiece. Within the scope of this paper, a process was developed which allows the integration of flexible as well as stiff impregnated textiles into the extrusion process. For this purpose, different textile-reinforced mortars (TRM) were extruded and their material characteristics were investigated. The results show that the mortar cross-section is considerably strengthened, especially when using carbon textiles, and that extrusion has considerable potential to produce high-performance TRM composites. In uniaxial tension tests with TRM, as well as in the pure roving tensile strength tests, textile stresses of approx. 1200 MPa were achieved for the glass textile and approx. 2250 MPa for the carbon textile. The position of the textile layer deviated a maximal 0.4 mm from its predesigned position, which shows its potential for producing tailor-made TRM elements. In addition, by adjusting the mortar mix design, it was possible to reduce the global warming potential (GWP) of the extrusion compound by up to 49.3% compared to the initial composition from preliminary studies.


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