Effect of Accelerating Admixture on Properties of Concrete International organization of Scientific Research 50 | P a g e increase in compressive strength was observed at 28 days with respect to reference mix. Compressive strength for concrete mix with 3% sodium nitrite by weight of cement was found to be less than that of reference mix. 1.2.2.
The importance of controlling concrete temperature is well understood. Temperature affects fresh and hardened properties of concrete as well as the thermal cracking potential. Careful attention must be paid to batch temperatures in hot and cold weather concreting. However, as evidenced by the graph below, the relative effect of hot cement on ...
Setting Time Cement paste setting time is affected by a number of items including: cement fineness, water-cement ratio, chemical content (especially gypsum content) and admixtures. For construction purposes, the initial set must not be too soon and the final set must not be too late.
Static and dynamic mechanical properties of concrete are affected by temperature effect in practice. Therefore, it is necessary to investigate the corresponding influence law and mechanism. This paper demonstrates the variation of mechanical properties of concrete at temperatures from −20°C to 60°C. Temperature effects on cube compressive strength, splitting tensile strength, prism ...
KEYWORDS: Casting temperatures,curing compressive strength, final set,initial slump, temperature effects. ABSTRACT: Concretes, made with two different cements, were cast in the laboratory at temperatures of 10,23 and 32°C (50, 73, and 90"F). The concrete mix design was held constant for each cement used in the study. Fresh properties,
Influence of cement type on heat of hydration and temperature rise of the mass concrete M H Leea, B S Khilb & H D Yuna* aDepartment of Architectural Engineering, Chungnam National University, 99 Daehak-ro Yuseong-gu, Daejeon 305-764, Korea bTripod Company, Daejeon, 305-308, Republic of Korea Received 31 October 2013; accepted 9 June 2014
Nov 02, 2015· High Exit vent temp at cement mill outlet. We have open circuit ball mill grinding OPC 43 grade, feed moisture 2% max, Inlet temp 35 Deg C and outlet temp we are getting around 90 to 95 deg C, what could be the reason of high temp at mill outlet, since we have not supplied hot gas at feed, can anybody suggest the possible reason please, which helps to take necessary action.
As with any material, concrete will expand and contract as the temperature rises and falls. The size of movement depends upon the change in temperature and the coefficient of thermal expansion o f concrete. The coefficient of thermal expansion of concrete is influenced largely by the coefficient of ...
building research journal volume 56, 2008 number 2–3 157 effect of elevated temperature on the physico-mechanical and microstructural properties of blended cement pastes
When the peak concrete temperature is decreased, thermal expansion and cracking is also decreased. 5. Chemical and mineral admixtures can be used to improve concrete properties (water reducer is to decrease the water demand of a concrete mix). 6 6. Increasing cement fineness has no affect on total heat of hydration at 7 days. 7.
and the properties of the hardened cement paste: that variable is temperature [1]. A recent paper [2] concluded that high curing temperatures raised the very early compressive strength of sulphate-resistant cement, but had an adverse effect on mechanical properties at curing times of over 15 days.
Studies conducted on the effect of clinker free lime on the cement properties were very low and for the purpose of producing quality material, we studied the effect of the clinker free lime on the cement physicochemical properties, like: the expansion, the setting time and the compressive strength. For this, two types of clinker were
Home / Concrete Technology / Concrete Properties / Factors Affecting Strength of Concrete Concrete strength is affected by many factors, such as quality of raw materials, water/cement ratio, coarse/fine aggregate ratio, age of concrete, compaction of concrete, temperature, relative humidity and curing of concrete.
Because the use of chemical and mineral admixtures in addition to air-entraining agents has become common practice, concrete users are always concerned about the effects of these admixtures on the air-void system and durability of concrete. Effects of water reducers, retarders, and accelerators were widely investigated by many researchers.
mechanical and physical properties of blended cement concrete subjected to heat, containing micro silica (silica flour) as pozzolanic materials. These properties are very important for a safe design of concrete and in the repair of concrete structures. II. EXPERIMENTAL WORK A. materials Effect of Elevated Temperature on Mechanical
The influence of orthophosphates on the properties of portland cement Ceramics – Silikáty 58 (4) 282-287 (2014) 283 extends the service life of furnace fire brick [13-15]. The most impurities in phosphogypsum can be found in the particle size fractions above 160 μm and below 25 μm. There are more than few plants
materials Article The Effect of Curing Temperature on the Properties of Cement Pastes Modified with TiO2 Nanoparticles Karine Pimenta Teixeira 1, Isadora Perdigão Rocha 1, Leticia De Sá Carneiro 1, Jessica Flores 1, Edward A. Dauer 2 and Ali Ghahremaninezhad 1,* 1 Department of Civil, Architectural and Environmental Engineering, University of Miami, Coral Gables,
Cement properties especially water demand and strength development ... The European Cement Research Academy (ECRA) has decided to broaden its research ac- ... The raw mix is then dried and ground in the raw mill be-fore fed to the kiln as powder with R90µm of .
When the peak concrete temperature is decreased, thermal expansion and cracking is also decreased. 5. Chemical and mineral admixtures can be used to improve concrete properties (water reducer is to decrease the water demand of a concrete mix). 6 6. Increasing cement fineness has no affect on total heat of hydration at 7 days. 7.
Effect of high temperature on mechanical and physical properties of lightweight cement based refractory including expanded vermiculite F. Koksal1, O. Gencel2,3, W. Brostow*3 and H. E. Hagg Lobland3 Four different composite mixtures with varying amounts of expanded vermiculite were exposed to
Nevertheless, no standard specifications have been developed. Water- the effect of quality of water used in concrete has not been studied in relation to performance of concrete under high temperatures. However, it is assumed that the relationship would not extend beyond the effect of water quality on strength of the concrete at room temperature.
Cement is seldom used on its own, but rather to bind sand and gravel together. Cement mixed with fine aggregate produces mortar for masonry, or with sand and gravel, produces concrete. Cement is the most widely used material in existence and is only behind water as the planet's most-consumed resource.
temperature of the cement leaving the mill will be dependant on the temperature of the materials (especially the clinker) fed to the mill and to features of the mill and the grinding process. It will typically be in the range from 90 to 120 deg. C. At this temperature-level the water of crystallisation of the gypsum added to the mill will
The colouring effect of Fe, Cr, and Mn cations depends on their valency in the crystalline phases in cement. Oxidized forms of free oxides of Fe3+, Mn3+ and Mn 4+ absorb more light than reduced forms Fe 2+ and Mn2+.The higher the temperature and/or the