Feb 17, 2014nbsp018332The replacement levels of OPC by Silica Fume were 0, 2.5, 5, 7.5, 10, 15 and 20 where replacement levels of OPC by Fly Ash were 0, 5, 10, 15, 20, 25 and 30. 1 super-plasticizer was used in all the test specimens for high performance i.e., high workability at lower water-binder ratio and to identify the sharp effects of Silica ...
This replacement was made by considering water-cement ratio as 0.45 and it has been observed that about 5 replacement of cement by microsilica cement improves compressive strength and flexural strength of the concrete specimens. index terms fly-ash, slag, micro-silica, concrete ... 2004 effect of silica . fume on the mechanical properties ...
Effects of silica fume and fly ash on the properties of concrete. water-binder ratio was kept 0.42 for all cases and the specimens were tested at ages of 7, 14 and 28 days.10 silica fume and 20 fly ash showed the lowest water penetration depth of 11mm and 15 mm respectively. 7.5 silica fume and 10 fly ash were found to be optimum for maximum
Effects of silica fume and fly ash. if the dosage of sp is varied with the silica fume and fly ash replacement percentage, then the variations in the concrete strength will occur not only due to variations in the silica fume or fly ash contents but also due to change in the dosage of sp 6.
The reason for gain of strength in fly ash cement ppc could be fast reaction between fly ash and silica-fume particles due to fine nature. 44.73. it is observed that up to 12 replacement of cement with silica fume the compressive strength increases with increasing dose of silica fume
Production as partial replacement of cement. fly ash and silica fume can be used as filler and helps to reduce the total voids content in concrete. the cement has been replaced by fly ash accordingly in the range of 0, 25, 30, 35, 40, 45, 50, 55 and 60 by weight of cement and 10 of silica fume in common for m-30 mix.
7 namagg amp ataderoet.al, 2009 used fly ash for partial replacement of cement and fine aggregates. 0 to 50 was tested in their study. conclusion from the research studies of fly ash concrete and the research study of silica fume concrete conclude that conclude that the use of both sf and fa will be overall beneficial
4. slump loss of concrete goes on increasing with increase of quantity of fly ash. 5. the 10 and 20 replacement of cement with fly ash shows good compressive strength for 28 days. 6. the 30 replacement of cement with fly ash ultimate compressive strength of concrete decreases. 0 10 20 30 40 50 m 0 10 20 30 of fly ash 0 5 10 15 20 25 30 ...
Without silica fume. concrete containing silica fume shows substantial reduced bleeding. additionally, silica fume reduces bleeding by physically blocking the pores in the fresh con-crete. use of silica fume does not signi cantly change the unit weight of concrete. 2.4 effect of silica fume on the hardened properties of cementmortarconcrete
Jan 31, 2016nbsp018332effects of fly ash on concrete 1. on amount of mixing water. the use of fly ash in limited amounts as a replacement for cement or as an addition to cement requires a little more water for the same slump because of fineness of the fly ash. it is generally agreed that the use of fly ash, particularly as an admixture rather than as a replacement ...
A superplastisizer 1 by weight of cement was added to this slurry which increased infiltration capacity of the slurry. to study the effect of replacement of cement by silica fume on sifcon, slurry was prepared by replacing cement by silica fume at varying percentages like 5, 10, 15, 20, 25 and 30 by weight of cement.
Jun 01, 2011nbsp018332in addition to investigate the effect of curing conditions on concrete compressive strength. all test specimens are 100 mm in diameter and 200 mm in length as show in fig. 1. in this study, the major test parameters are cement content, the percentage of fly ash, the percentage of silica fume, and water curing periods.
Effect of cement replacement with micro silica in the production of high standard size of cubes for the strength concrete. yogendran et al, 1987, investigated on silica fume in high strength concrete at a constant water binder ratio wb of 0.34 and replacement percentages of 0 to 25, with varying dosages of hrwra. the maximum 28 day
Title fly ash concrete 1 fly ash concrete 2 fly ash concrete. fly ash is a fine, glass like powder recovered from the gases of coal fired electricity production inexpensive replacement of portland cement improves strength,segregation and ease of pumping the concrete 3 history . first used in 1929 in the construction of the hoover dam
In developed countries use of mineral admixtures such as fly ash, silica fume has already been adopted in making concrete. this includes commercial application
The mixtures were prepared with 100 of a type 10 cement, a blended silica fume cement containing 8 silica fume, as well as a class f fly ash used at 20 replacement. all mixtures were made with a 0.41 water-to-cementitious materials ratio and had initial slump values of 230 5 mm 9.1 0.2 in..
Jan 26, 2017nbsp018332silica fume concrete silica fume is an artificial pozzolona having high pozzolonic activity. it is a by- product from an electric arc furnace used in manufacture of silicon metal or silicon alloy. it has high silica content of more than 80. it is an excellent for use as a portland cement supplement. 4. silica fume concrete 5.
Jan 10, 2019nbsp018332in this study, the effect of foam content 0.0, 31.4 and 47.1, by volume, and partial 0, 10 wt and 20 wt replacement of cement with fly ash fa and silica fume sf on the density, water absorption, compressive strength and thermal conductivity of foam concrete was researched after 7-day and 28-day standard curing as well as autoclave ...
Fly ash concrete powerpoint ppt presentations. all time show ... behavior of m25 grade concrete with partial replacement of fly ash and rice husk ash - comparison of behavior and strength of concrete in m 25 grade mix design for 7 days and 28 days. comparison of behavior and strength of concrete in m 25 grade mix design for 7 days and 28 days ...
Use of fly ash in concrete. the use fly ash in concrete has dramatically increased in the last 20 years. you can get fine high volume product from the high volume fly ash suppliers company. for economic ecological benefits, the utilization of fly ash in concrete enhances its workability, plus it lessens segregation, heat evolution permeability.
However, the effectiveness of fly ash to suppress the expansion of mortar was different when the chemical composition or physical property of the fly ash was different. it is shown that the suppressing effect of the fly ash was affected by the content of amorphous silica and the specific surface area of fly ash.
Self compacting mixtures had a cement replacement of 20, 30 and 40 with class f fly ash and 5, 10 and 15 with silica fume. the results show that normal strength self compacting concrete could be successfully produced using fly ash and silica fume.
Fly ash is used in about 50 of ready mixed concrete pca 2000. class f fly ash is often used at dosages of 15 to 25 by mass of cementitious material and class c fly ash is used at dosages of 15 to 40 by mass of cementi-tious material. dosage varies with the reactivity of the ash and the desired effects on the concrete helmuth 1987 and
To study the effect of fly ash and silica fume in the compressive strength characteristic of high performance concrete specimens were cast and for the combination mentioned in table 3 fly ash has been used as cement replacement material for 0, 10, 20 and 25 cement replacement level with different values of silica
A properly proportional fly ash and silica fume in concrete mix improves properties of the concrete that may effect of cement replacement by silica fume and fly ash explore effect of cement replacement by silica fume and fly ash with free download of seminar report and ppt in pdf and doc format. also explore the seminar topics
Apr 08, 2017nbsp018332objectives to study the effect of partial replacement of cement with fly ash and silica fume. evaluation of the compressive strength of high volume fly ash concrete. to find out the optimum percentage of replacement of fly ash. to know the strength variations with use of fly ash and silica fume to the normal concrete. 5.