A Low-Cost, Computer-Controlled Adiabatic Calorimeter for Determining the Heat of Hydration of Concrete

1997 ◽  
Vol 25 (2) ◽  
pp. 261 ◽  
Author(s):  
DR Petersen ◽  
RE Link ◽  
GJ Gibbon ◽  
Y Ballim ◽  
GRH Grieve
Keyword(s):  
Low Cost ◽  
Adiabatic Calorimeter ◽  
Heat Of Hydration ◽  
Computer Controlled

Fixturing of Compliant Parts Using a Matrix of Reconfigurable Pins

1999 ◽  
Vol 122 (4) ◽  
pp. 766-772 ◽  
Author(s):  
Daniel F. Walczyk ◽  
Randy S. Longtin
Keyword(s):  
Low Cost ◽  
Metal Composite ◽  
Lateral Loads ◽  
Load Carrying ◽  
Mechanical Models ◽  
Computer Controlled ◽  
Compliant Parts ◽  
Plastic Parts ◽  
Machining Operations ◽  
Rigid Platen

Commercially-available reconfigurable fixtures, used for holding compliant sheet metal, composite and plastic parts during secondary machining operations, are extremely expensive and overly-complicated devices. A computer-controlled, reconfigurable fixturing device (RFD) concept for compliant parts, based on a matrix of individually-stoppable pins lowered by a single rigid platen, has been developed as a simple and low-cost design alternative to commercially-available devices. Two different approaches to stopping and clamping individual pins have been investigated: a combination electromagnet assist and gas springs compressed with a toggle mechanism, and a pneumatic clamp. Simple mechanical models have been developed for predicting the stopping and clamping performance of both designs including pin positioning accuracy, vertical load-carrying capacity of a pin, and deflection of a pin subjected to lateral loads. An RFD prototype, consisting of a single pin actuated by a servoed platen, has been designed, built and tested. It has demonstrated the feasibility of this new RFD design. [S1087-1357(00)02204-8]

A Low Cost Computer Controlled IC Engine Test Facility

1998 ◽  
Vol 31 (4) ◽  
pp. 105-109
Author(s):  
Z. Ren ◽  
T. Campbell ◽  
J. B. Yang
Keyword(s):  
Low Cost ◽  
Test Facility ◽  
Engine Test ◽  
Ic Engine ◽  
Computer Controlled

Design of a simple, low-cost, computer-controlled, dual-beam optical tweezer system

Optik ◽  
2016 ◽  
Vol 127 (1) ◽  
pp. 440-446 ◽  
Author(s):  
C.J. Firby ◽  
K.N. Smith ◽  
S.R. Gilroy ◽  
A. Porisky ◽  
A.Y. Elezzabi
Keyword(s):  
Low Cost ◽  
Optical Tweezer ◽  
Dual Beam ◽  
Computer Controlled

scholarly journals Behavior of RPC based Alkali Activated Material Compared with Conventional RPC

2020 ◽  
Vol 9 (8) ◽  
pp. 602-607 ◽  
Keyword(s):  
Silica Fume ◽  
Low Cost ◽  
New Technology ◽  
High Heat ◽  
Heat Of Hydration ◽  
Cement Industry ◽  
Engineering Properties ◽  
Thermal Curing ◽  
Reactive Powder ◽  
Alkali Activated

Reactive Powder Concrete (RPC) is a type of high strength concrete that is characterized by its excellent engineering properties. Inclusion of high silica fume contents and high cement demand are the most essential parameters in the development of RPC. Silica fume is a highly cost and unavailable material in many countries. Cement industry is not a sustainable eco-friendly process. High heat of hydration and many shrinkage cracks are also the most shortcomings obtained from cement utilization. Therefore, it’s urgently required to replace the utilization of silica fume and cement with partially or totally environmental friendly materials in the production of RPC. Metakaoline (MK) is a low cost, available and high pozzolanic material that can substitute silica fume in concrete. Alkali Activated Materials (AAM) binders are new technology that can totally replace the cement in concrete. The main objective of this study is to evaluate the performance of RPC based cement developed by MK and the performance of RPC based AAM under different curing conditions. Slag and MK are the used AAM in this research which are eco-friendly, sustainable and quite available materials in Egypt. The engineering properties like compressive strength and sorptivity are studied to investigate the behavior of RPC. It was concluded that thermal curing has shown a good impact in the performance of all RPC mixes. MK has shown satisfied results in the behavior of RPC based AAM under thermal curing. Slag shows better mechanical and durability properties that resemble the behavior of the conventional RPC based cement.

Bubbled Roller Compacted Concrete Dam: an idea of a hollow dam

2022 ◽  
pp. 1-25
Author(s):  
Ezzeldin K. Mohamed ◽  
Eehab Khalail
Keyword(s):  
Bearing Capacity ◽  
Low Cost ◽  
Heat Of Hydration ◽  
Gravity Dams ◽  
Construction Time ◽  
Concrete Dam ◽  
Roller Compacted Concrete ◽  
Construction Methods ◽  
Roller Compacted Concrete Dam ◽  
Dam Stability

Roller compacted concrete is widely known for its relatively low cost and short construction time. RCC gravity dams require high foundation (rock) bearing capacity. Research has been carried out which proposes to rationalise the amount of material in the dam by creating inner voids, in the shape of bubbles. As a key requirement, the introduced bubbles should not affect the dam stability and safety. The bubbles will reduce the self-weight of the dam and minimise the required rock bearing capacity. A system of pipes connecting the bubbles ensures drainage of the bubbles. The proposed dam would save about 12% of the required concrete volume. Different construction methods were studied and the best alternative is the use of precast hollow boxes. This decreases RCC placement in the dam by 32.5%. The objective is to speed the construction process and minimise the risk of the heat of hydration.

Pozzolanic Reaction Effects of Red Mud on Hygrothermal and Microstructural Properties of Cementitious Composites

2014 ◽  
Vol 600 ◽  
pp. 319-328 ◽  
Author(s):  
Eliz Paula Manfroi ◽  
Malik Cheriaf ◽  
Janaíde Cavalcante Rocha
Keyword(s):  
Red Mud ◽  
Pozzolanic Reaction ◽  
Adiabatic Calorimeter ◽  
Heat Of Hydration ◽  
Cementitious Composites ◽  
Microstructural Properties ◽  
Cement Pastes ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Alumina Industry

The alumina industry produces the red mud (RM) as one of its by-products. The red mud waste has pozzolanic potential, mainly when calcined at 600oC. In this paper, the microstructure of cement pastes constituted by 15% of dry and calcined red mud at 600, 700, 800 and 900oC were investigated by scanning electron microscopy analysis. To assess the evolution of the heat of hydration of pastes produced with until 15% of red mud in replacing the cement was used a semi-adiabatic calorimeter. Water absorption by capillarity and wetting angle tests were realized on mortars constituted by 5 and 10% of red mud in replacement of cement. The images of the microstructures of the pastes produced with red mud showed the formation of the hydration products calcium silicate hydrate, fase AFm (monosulfate) and ettringite. The pastes produced with 5, 10 and 15% red mud showed higher heat of hydration than the reference pastes (only cement). The mortars produced with 5% of dry and calcined red mud at 600, 700, 800 and 900oC showed lower sorptivity than the reference mortar. The results shown that the replacement of the cement by red mud waste influence in the hygrothermal and microstructural properties of cementitious composites.

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