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Cement evaluation logs and other cased-hole logs can indicate the strength of the set cement and whether it "s bonded to the cas.ng (far right). The out- come of a cementing job, however, depends ultimately on choosing the appropriate cement and additives to cope with particu lar well conditions. . Portland cement was developed by Joseph Aspdin


concrete from the adverse effects of hot weather, admixtures are usually incorporated in it. The objective of this paper is to investigate the effects of a retarding admixture (ASTM C 494 Type D) on setting time of cement pastes. The setting time tests were performed under three different curing conditions (temperature & relative humidity).


Accordingly, a curing time of seven days could be established as a threshold level to set a minimum curing time for mortar with a content of ground granulated blast-furnace slag higher than 28%; whereas a curing time of three days could be enough for cement-based materials with less than 28% blast-furnace slag .


Answer (1 of 27): Division on setting time of cement is based on Initial setting time of cement and Final setting time of cement. Generally Initial setting is the time elapsed between the moment water is added to the cement to the time at which paste starts losing its plasticity. Final setting ti...


Slag cement does not contain carbon and does not cause instability in the entrained air content. Time of Set. Time of initial set is influenced by the use of slag cement and fly ash. Concrete made with slag cement can have faster set times than concrete made with fly ash (Figure 2). Pumpability and Finishability. Pumpability with slag cement ...


Slag cement begins in an iron blast furnace. Carefully controlled amounts of iron ore, along with limestone or dolomite, are fed into a blast furnace and heated to 2,700 degrees F. When molten, the iron is tapped for steel production and the slag is diverted to a granulator. Here, the slag is rapidly quenched with large quantities of water.


In order to investigate the effect of Cr6+ on the properties of alkali-activated slag cement (AAS), the effects of added dosage of Na2Cr2O4 on the setting time and compressive strength of AAS were measured. The leaching concentration of Cr6+ from AAS cement stone was measured using dual-beam UV-visible spectrophotometry. The effect of Na2Cr2O4 on the hydration kinetics of AAS cement was ...


10. GGBF slag's has no negative effect on the corrosion of steel (Fulton 1974; Lea 1971; Hogan and Meusel 1981). It has been found that a slight reduction in the pH of pore solution does not have a negative impact on the passivity of reinforcing steel, and that use of GGBF slag in good quality concrete, reduces concrete per-


This study addresses the amount of the delay in set time and strength gain and the effect on the time between initial and final set as compared to non -GGBFS concrete. ASTM C 989 (Standard Specification for GGBFS for use in Concrete and Mortars), adopted in November 1982, provides for three strength grades of GGBFS depending


Slag cement performs very well up to 50% slag cement "Good"concrete will scale if not finished/cured properly In laboratory studies: Scaling tends to increase with higher levels of slag cement or fly ash At high levels of slag (>50%) or fly ash (>25%), scaling can reach a high level Stoney Creek, Ontario Test Pavements Dike 6 mm of salt ...


Initial and final setting times of cement, which are determined using the Vicat needle test, are used as a quality control measure for cement characterisation (EN-196, 1995) and specified as a requirement in related standards (EN-197, 2011; ASTM C150, 2015).A comparison between the initial and the final setting time of cements manufactured with and without CS (Alp et al., 2008; Supekar, 2007 ...


Answer (1 of 3): Basically you must add additive For Cold Weather * Hot water-Your ready mixed concrete producer will usually have, and use, hot water in the concrete when the weather turns cold. Most producers will try to have the concrete be at least 65°F when it leaves the plant, which is gen...


Slag cement concrete sometimes turns green for a short period of time due to the oxidation state of sulfide sulphur compounds during portland/slag cement hydration. This is normally a temporary condition and the concrete, upon exposure to air and sunlight, will ultimately become lighter than portland cement concrete.


At one time 250 g of ferrochrome slag material was taken in the jar and ground in a high-energy ball mill for 30 min at 400 rpm. Similarly, it was processed to complete the grinding of complete material. The ground material was then kept in various selected sieves and set up on the motorized vibro-sieving equipment for grading.


RE: Slag set time in cold weather. concretemasonry (Structural) 13 Dec 07 15:50. No question about the retarding effects or slow strength gain when you are using fly ash and slag. The cool weather temperatures magnify the effects, no matter what the concrete temperature at placement. Even though you may get a 28 day cylinder strengths specified ...


Slag is sensitive to the alkali content of the cement (and fly ash) and is sensitive to temperature. So if your cement is a low alkali (Na2O) it will gain strength slower with slag than with a higher alkali content cement. Setting times. A consequence of the pozzolanic nature of the cementitious materials is that they will not set quickly.


This can catch a concrete crew off guard and miss the opportunity to put a nice tight surface on a slab. If the placement is not a steel-troweled slab, these affects may be irrelevant. Remember that slump loss does not equal set time. Set time may be delayed but the slump may still decrease over time, causing placement issues.


The addition of slag has a great effect on the setting time of the MKPC. The setting time increases with increasing slag content. The setting time of MKPC reaches 65 min when the slag content is 20 wt%, which is sufficient for field operations. (2) A large slag content negatively affects the compressive strength of MKPC.


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Slag Cement: The Other SCM

Slag cement, previously known as ground-granulated blast-furnace slag ⠀䜀䜀䈀䘀, has been used in concrete for well over 100 yeൡrs ⠀䄀䌀䤀 ㈀ ㄀㄀. The first recorded production in the US of blended cement containing both slag and portland cement was in 1896 ⠀䄀䌀䤀 ㈀ ㄀㄀.


Initial Setting Time of Cement. Initial setting time of cement is the time when the paste (cement + water) starts losing its plasticity. This mean that if the initial setting time of cement is 30 minutes, the cement mortar or concrete must be placed in position within 30 minutes of adding water. If delayed, mortar or concrete will lose strength.


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Slag cement strength

Slag cement increases the compressive and flexural strength of conventional concrete (Figures 1 and 2) and is often a vital component in producing high strength concrete. 28-day strengths generally increase as the percentage of slag cement increases, up to about50 percent slag cement as a percent of cementitious material.


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What is slag cement

Slag cement is commonly found in ready-mixed concrete, precast concrete, masonry, soil cement and high temperature resistant building products. While there are many applications and benefits of slag cement, a few are highlighted below and detailed information sheets are located here .


Generally speaking, if mixed materials are added into the cement clinker, the anti-erosion will increase, and the heat of hydration and the early strength will decrease. (2) The Mixing Amount of Gypsum. Gypsum is called the retarding agent of cement which is mainly used for regulating the setting time of cement and is an indispensable component.


Slag cement is commonly found in ready-mixed concrete, precast concrete, masonry, soil cement and high temperature resistant building products. While there are many applications and benefits of slag cement, a few are highlighted below and detailed information sheets are located here.


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Slag Cement Questions

Slag cement concrete sometimes turns green for a short period of time due to the oxidation state of sulfide sulphur compounds during portland/slag cement hydration. This is normally a temporary condition and the concrete, upon exposure to air and sunlight, will ultimately become lighter than portland cement concrete.


Quality and durability, on the other hand, are dependent on what occurs from the time the concrete mix has been placed in the mold. Settlement and Bleeding . Concrete is said to be in a plastic state before it begins to set. The aggregate is dispersed by the cement paste and the particles in the paste are dispersed in the water.


Question: What Effect Does Blast Furnace Slag Have On Set Time Of Concrete, And What Effect Does It Have On The Permeability Of Concrete? (1 Mark) 7. (1 Mark) 7. This problem has been solved!


Use of Admixture and Its Effects on Setting Time. Initial set, as defined by ACI 116R, is a degree of stiffening of a mixture of cement less than final set, generally stated as an empirical value indicating the time in hours and minutes required for the cement paste to stiffen sufficiently to resist to an established degree, the penetration of a weighted test needle.


When a mix is easily making strength, there is often the urge to reduce the cement content, but this will have a negative effect on the finishability. Slag cement or fly ash replacement of cement will typically increase the volume of the paste as their specific gravity is less then cement.


Cement containing large amounts of alkali can cause some difficulty in regulating the setting time of cement. Low alkali cement, when used with calcium chloride in concrete, can cause discoloration. In slag-lime cement, ground granulated blast furnace slag is not hydraulic on its own but is "activated" by addition of alkalis.


The effect of a partial replacement of cement with slag cement on free shrinkage is evaluated for curing periods between 3 and 28 days. Mixtures include concrete containing different replacement ...


Final Setting Time is defined as the period elapsing between the time when water is added to cement and the time at which the needle of 1 mm square section with 5 mm diameter attachment makes an impression on the test block . 600 minutes is the maximum time specified for the final set for all the above mentioned Portland cements.


Effect of slag content to cement grout on the compressive strength development in tropical weather environment ... Slag cement has been around for a l ong time. Its history parallels that of ...


same factors affect the set time of concretes made with slag cement as with ordinary portland cement. Generally, the higher the slag cement dosage, the slower the set time. This provides some advantages during hot weather concreting. Retarding admixtures and cold weather tend to slow set times for slag cement concretes.