Revised Procedure for the Determination of Uncombined Lime in Portland Cement

Lerch, William; Bogue, R. H.

doi:10.1021/ac50071a036

Cited by 26 publications

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“…Examinations for free lime were made on each of the quenched and crystallized compositions by White's (13) method and by the ammonium acetate method [14). All quenched compositions gave negative results by both methods, which indicated the absence of free lime.…”

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Method for approximating the glass content of portland cement clinker

Lerch¹,

Brownmiller²

1937

J. RES. NATL. BUR. STAN.

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This report describes a method for approximating the glass content of portland cement clinker. The method involves a determination of the heat of solution of the original clinker and of the same clinker which has subsequently been annealed under conditions designed to produce complete crystallization. The difference between the heat values so obtained is due principally to the latent heat of crystallization of the glass present in the original clinker. The ratio between that value and the latent heat of crystallization of the glass phase represents the glass content of the clinker. A curve is given showing the latent heat of crystallization of all possible glass compositions obtainable from melts at 1,400° C in the system CaO-AI20.Si02-Fe20g between the A120g/Fe203 ratios of 0.64 and 3.24.

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confidence: 99%

Method for approximating the glass content of portland cement clinker

Lerch¹,

Brownmiller²

1937

J. RES. NATL. BUR. STAN.

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“…Bulk chemical compositions of the OPC, silica fume and hydrated cement pastes were determined using a PANalytical Axios Advanced XRF spectrometer at Leicester University, Department of Geology, and carbonate content was determined using acid digestion in an Eijkelkamp calcimeter with reproducibility better than ±0.6% CaCO 3 . Free lime in the cement and untreated calcium silicate hydrate gels was determined in accordance with the methods in Swendon and Throvaldson (1950) and Lerch and Bogue (1930).…”

Section: Experiments Amentioning

confidence: 99%

Laboratory carbonation of artificial silicate gels enhanced by citrate: Implications for engineered pedogenic carbonate formation

Renforth

Manning

2011

International Journal of Greenhouse Gas Control

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a b s t r a c tCarbon dioxide sequestration through carbonation of calcium or magnesium-rich silicate materials is a geoengineering technology that could mitigate a substantial proportion of anthropogenic emissions. Contemporary mineral carbonation research considers optimising this process to overcome energy requirements for mineral pre-treatment and reactor operation. This paper compliments previous studies in this area by demonstrating enhanced weathering through the action of organic acids including those exuded by plant roots. Batch weathering experiments, conducted as part of this study, with hydrated cement gels have shown that up to 80-85% of calcium is leached from the material in 5 h when exposed to solutions containing citrate anions, at an approximate log weathering rate between −8.26 and −6.86 molCa cm −2 s −1 , which is much more rapid than observed carbonate precipitation rates in previous studies for urban soils that contain cement-derived minerals. Thus Ca availability is not rate limiting. Coupled silicate-dissolution/carbonate precipitation reactions provide a carbon sequestration function that can be designed into soils specifically engineered to facilitate carbon capture.

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“…The alcohol-glycerol method (8) has been used in this laboratory for many years for determining free lime in Portland cement and in preparations of silicates and aluminates of calcium. In the present study no extended work with commercial cements was undertaken.…”

Section: Determination Of Free Lime In a Portland Cement And A Portlamentioning

confidence: 99%

The Alcohol–glycerol Method for the Determination of Free Lime

Swenson¹,

Thorvaldson²

1951

Can. J. Chem.

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A study was made of the alcohol-glycerol method of determining free lime in Portland cement and in mixtures of some aluminates and silicates of calcium.Strontium chloride is an effective accelerator. Calcium chloride is effective for mixtures of the pure silicates, but with Portland cement both it and calcium acetate give reduction of the total time required only a t low concentrations and produce low values for free lime a t higher concentrations of the salts. Lithium chloride produces acceleration, but magnesium chloride masks the presence of free lime. Addition of water in small amounts reduces the time required for the determination; larger amounts cause high values for free lime in the presence of tr~calcium silicate.Lime heated to high temperatures becomes too inert to be determined without reactivation by suitable accelerators.The presence of 5:3 calcium aluminate and alumina interfere with the determination of free lime. The method is not satisfactory for underburnt limealumina-silica systems low in tricalcium sillcate but is more suitable for such systems high in this compound. The higher values obtained with accelerators are probably more accurate than those obtained without accelerators. High precision may be attained with mixtures of dicalcium silicate, tricalcium silicate, and triwlcium aluminate.The alcohol-glycerol method (4,8) or this method in modified form, (1, 3 , 5 ) is probably the one most generally used for the determination of free lime in Portland cement. Extensive co-operative work (5, G) in the evaluation of these and other methods has indicated preference for the method of Lerch and Bogue (8) on the basis of precision. The length of time required is a disadvantage, but this may be a t least partly remedied by the use of barium chloride (1, 3) or sodium chloride (5) as accelerators. The wide variation in the results obtained by cement chemists in different laboratories (5), however, indicates that there are still difficulties in the execution of all these methods.The object of the present work was to study the effect of varying conditions, the use of accelerators, and the use of the method in determining free lime in mixtures of the aluminates and silicates of calcium.

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Revised Procedure for the Determination of Uncombined Lime in Portland Cement

Cited by 26 publications

References 0 publications

Method for approximating the glass content of portland cement clinker

Method for approximating the glass content of portland cement clinker

Laboratory carbonation of artificial silicate gels enhanced by citrate: Implications for engineered pedogenic carbonate formation

The Alcohol–glycerol Method for the Determination of Free Lime

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