Use Of Glass Powder Research Articles

Pozzolanic reactivity of recycled glass powder at elevated temperatures: Reaction stoichiometry, reaction products and effect of alkali activation

Use of glass powder as concrete SCM or in development of lime–pozzolan binders could provide environmental and economical benefits. In exposure to an alkaline pore solution, glass powder (GP) dissolves and reacts pozzolanically with calcium hydroxide (CH). In this paper, the stoichiometry and products of this reaction are studied using a CH–GP binder system cured at 60°C. TGA, selective acid dissolution, SEM/EDS, and QXRD methods are used to quantify the stoichiometry, and characterize the reaction products as a function of age. It is determined that approximately equal masses of CH and GP react with each other and with water to produce C–S–H. Both crystalline and amorphous C–S–H are formed, but the crystalline C–S–H is favored at later ages and higher alkalinities. NaOH-activation accelerates the reactions. However when high alkalinity is maintained, GP continues to dissolve after complete consumption of CH, and forms alkali–silicate gels, which could be expansive and deleterious.

Stoichiometric study of activated glass powder hydration

The focus of this work was to study the reactivity of glass powder of a certain fineness by using a new experimental approach and to establish specifications for the use of glass powder as a pozzolanic material in concrete by developing glass powder hydration reaction equations. Experiments were carried out to determine the different quantities and proportions of glass powder, calcium hydroxide and water to establish the hydration reaction. Models that describe the hydration of the glass powder with and without calcium hydroxide are also developed in this paper. The developed models are validated using the results of the experiments. Using these models, predictions of the structure of the hydration products are obtained.

粉体系焼却灰を原料とする溶融ガラスパウダーの生成条件の検討

Huge amount of ash is generated from industrial wastes. In order to recycle this, the production of glass powder from ash is very useful because the use of glass powder as filler for concrete improves its properties. The purpose of this study is to clarify the formation mechanism of glass powder from powder ash and to obtain an optimum condition for its production. In this study, three kinds of ashes (sewage sludge ash, paper sludge ash, and coal ash) were used for the production of glass powder. Glass fraction and the ratio of spherical particles for the glass powder were measured. The crystalline phases in the glass powder was identified, and melting behavior of the ashes was investigated. It was found that melting process is very important to produce spherical glass powder and that the basicity defined as the ratio CaO/SiO2 is a good measure to control the composition of the ashes for the glass powder production.

Increased sensitivity for detection of human cytomegalovirus in urine by removal of inhibitors for the polymerase chain reaction

The presence of inhibitors in urine interferes with the enzymatic reaction of the polymerase chain reaction (PCR) for detection of human cytomegalovirus (HCMV). To remove inhibitors, HCMV virions in urine were precipitated with polyethylene glycol, or DNA was extracted from urine by the use of glass powder and subjected to PCR followed by Southern blot hybridization with alkaline phosphatase-linked oligonucleotide probes. These simple, rapid methods increased significantly the sensitivity of PCR for detection of HCMV in urine.

A new method for extracting DNA or RNA for polymerase chain reaction

The use of glass powder suspension for the extraction of RNA or DNA was studied to simplify the procedures of polymerase chain reaction (PCR). Using this procedure, proviral DNA of human T-lymphotropic virus type-1 (HTLV-1) in the blood of an asymptomatic virus carrier and viral RNA of human immunodeficiency virus (HIV) in the blood of an AIDS patient were easily detected by PCR employing glass powder. The use of glass powder is a simple and highly efficient procedure for the extraction of DNA or RNA, and can be applied for routine PCR.

New Glass-work Techniques Made Use of Glass Powder

New Glass-work Techniques Made Use of Glass Powder