The process of bonding and grounding can be defined as providing an electrically conductive pathway between a dispensing container, a receiving container and an earth ground. Clean the contact surfaces on the mounting area ground plane. Choose from 165 different sets of grounding and bonding flashcards on quizlet. Solid ground curing sgc sgc was a process developed by cubital inc. A curing practice involves keeping the concrete damp or moist until the hydration of concrete is complete and strength is attained. At certain locations, a point of diminishing benefit is obtained from ground rod installation. Accurate rapid prototyping by the solid ground curing technology.
These include high thermal and electrical conductivity, ease of manufacture, high recyclability and good corrosion resistance. Both the national fire protection association nfpa and the occupational safety and health administration. Solid ground curing sgc kyle stetz rapid prototyping. Earthing ranks right up there with the discovery of penicillin. As the basis of solid ground curing is the exposure of each layer of the model by means of a lamp through a mask. In this step, cad model is prepared and cross sections are generated digitally and transferred to the mask generator. This point is stressed in all industry standards, such as astm c 94, aci 318 and aci 301. Definitions bonding making a mechanicallysecure electrical connection between two or more objects to ensure they are at the. Page 2018 solidbase curing solid ground curing, sgc. Accelerated curing is any method by which high early age strength is achieved in concrete.
For initial curing of cylinders, there are two methods, use of which depends on the agency. This book is probably the most important health read of the twentyfirst century. Solid ground curing 3 d modeling production and manufacturing. Thermal and the ultravioletpost curing techniques have been in use for quite some time now. Construction industry use lot of water in the name of curing.
The eventual mechanical properties as well as the physical properties are greatly influenced by the post curing conditions used. Full text full text is available as a scanned copy of the original print version. For above ground applications, copper, aluminum and steel may be used. Examples of the processes most commonly associated with electrostatic ignitions. Curing begins immediately after placement and finishing so that the concrete may develop the desired strength and. Download as ppt, pdf, txt or read online from scribd.
This seminar is the first in a short series of electrical grounding and bonding webinars presented by neca. Astm c 31 practice for making and curing concrete test specimens in the. They may be the basis for acceptance testing for project concrete, research evaluations, and other studies. Curing of concrete purpose of curing curing methods. A variety of curing materials and techniques are available for use in concrete pavement construction. The highlighted features of cubital machine over the fdm or stereolithography are fastest making of models with huge volume of production at the same time. Nontinning general copper and copper alloys are widely used because they combine unique properties at an economical price.
The producer is responsible for providing concrete of consistent strength that will be subjected to a standard curing condition as defined by astm c 31. Selfcuring or internal curing is a technique that can be used to provide additional moisture in concrete for more effective hydration of cement and reduced selfdesiccation. The need for adequate curing of concrete cannot be overemphasized. The main process in making of model is successive layers of liquid photo polymer resins which are cured using the uv light. Nowadays, the additive technology industry is rather diverse. You must make a good contact to the ground, which can be a grounding rod driven several feet into the earth, or to an appropriately grounded water pipe or other approved ground. May 20, 2009 solid ground curing sgc sgc was a process developed by cubital inc. Standard practice for making and curing concrete test. Learn grounding and bonding with free interactive flashcards.
Rubber curing chemistry governing the orientation of layered. In the present study, the affect of curing compound. The post curing stage still remains a critical element in the processing ofmodels built using stereolithography. The sgc technology means a material that becomes fully solid, as the term suggests. Storage in open containers, expose to heat andor open flame. Technical notes on grounding and earthing methods, 225 b. Power, grounding, bonding, and audio for ham radio safety. Improved bonding and grounding methods for electrical. Soil resistivity and ground resistance for dry and wet soil. The american concrete institute aci defines internal curing as supplying water throughout a freshly placed cementitious mixture using reservoirs, via prewetted lightweight aggregates, that readily release water as needed for hydration or to replace moisture lost through evaporation or. Smoke or fumes may be evolved if heat of reaction becomes excessive due to high curing temperature or curing of large masses of material. The sgc process uses photosensitive resin hardened in layers as with the stereolithography sla process. Curing of concrete should begin soon after initial setting time of concrete or formworkshuttering is removed and must continue for a reasonable period of time as per the specified standards, for the concrete to achieve its desired strength and durability. The cubes were cured using six methods air curing, watersubmerged curing, spray curing, polythene curing, moist sand curing and.
Solid ground curing, also known as the solider process, is a process that was invented and developed by cubital inc. However, little is known about how different curing materials and tech. After thermal curing, they were subjected to normal curing for a period of 3, 7 and 28 days. The technology is no longer being produced, as cubital inc. The amount of barriers to healing is a long and sordid list, with a dirty food, water and air supply sitting at the top.
The software used, cubitals solider dfe data front end software, is a cad application package that processes prior to sending them. Curing has a strong influence on the properties of hardened concrete. Effect of curing methods on density and compressive strength. Annealing is warming a metal, usually steel, to give it a soft, easy shaped type of crystalline structure curing is the process of letting a metal sit to work out internal stresses that may have formed during a heat treatment sintering is reducing a metal to a powder and then pressing it together. The most commonly adopted curing techniques are steam curing at atmospheric. Rubber curing chemistry governing the orientation of. Rubber curing chemistry governing the orientation of layered silicate a. Heinrich leibnizinstitut fur polymerforschung dresden e. First, a cad model of the part is created and it is sliced into layers using cubitals data front end dfe software. They trap the moisture within the structure and prevent it from evaporation which normally occurs due to the hydration process.
Soil resistivity and ground resistance for dry and wet soil md. Sep 11, 2016 a curing practice involves keeping the concrete damp or moist until the hydration of concrete is complete and strength is attained. The first stage of rapid prototyping life cycle as a new technology in the marketplace is gradually ending, and the second stage has already started. Get a printable copy pdf file of the complete article 222k, or click on a page image below to browse page by page. The sgc process uses photosensitive resin hardened in. Be sure the copper wire connects solidly with the metal surface of the ground and to the metal. Abdus salam1, quazi mehbubar rahman2, swee peng ang1, fushuan wen1 abstract in this paper, soil resistivity and ground resistance at two different sites near an electrical substation are measured using a grounding system grid with and without rods. Principles of electrical grounding john pfeiffer, p. In bonding, the emphasis is on creating lowimpedance electrical connections between two or more conductive metallic bodies that are not normally currentcarrying. The overall process is illustrated in the figure above and the steps are illustrated below.
Self curing or internal curing is a technique that can be used to provide additional moisture in concrete for more effective hydration of cement and reduced selfdesiccation. Comparison of results compressive strength of slag based cement mortar was done with specimens cured in. In this step, a thin layer of photopolymer resin spread on the work surface. Many new vendors have introduced their products in this field, utilized different, new technologies or improvements of the.
Newson gales new grounding and bonding handbook includes. Provide a low resistance path for current to ground to ensure rapid isolation, should reenergization occur. Grounding and bonding as electrical installation protocols overlap to a certain extent, but they are not identical. Procedure initial curing when moving cylinder specimens made with single use molds support the bottom of the mold with trowel, hand, or other device. Solid ground curing process the scg process comprises of three main steps. Accurate rapid prototyping by the solid ground curing. Quality analysis and optimization of solid ground curing. This process is different from the previous in that a complete layer at a time is cured.
Effect of curing methods on density and compressive. You can apply them with spray equipment, such as handoperated pressure sprayers, to odd slab widths or shapes of fresh concrete, and to exposed concrete surfaces following form removal. However, if we can reignite our connection with the earth by grounding. I have included it here because it is an interesting and unique approach to printing. Curing is the maintaining of an adequate moisture content and temperature in concrete at early ages so that it can develop properties the mixture was designed to achieve.
This pathway helps eliminate the buildup of static electricity by allowing it to safely dissipate into the ground. Combine that with a poor relationship with the sun and the earth, and true healing becomes very difficult. These include high thermal and electrical conductivity, ease of manufacture, high recyclability and. Provide a work zone at or near ground potentia zero volts for the duration of the deenergized work. Curing compounds are generally economical, easy to apply, and maintenance free. Bonding and grounding of flammable liquids quick tips. Increase of the possible design iterations from 23 to 89. Careful and knowledgeable handling of materials, mixing concrete, molding test specimens, and curing test specimens is necessary. Johnston neca executive director, standards and safety 1 welcome to a neca webinar based on the national electrical code. Apr 12, 2016 grounding and bonding as electrical installation protocols overlap to a certain extent, but they are not identical. Accurate rapid prototyping by the solid ground curing technology nc. Whats the difference between annealing, curing and sintering. Solid ground is committed to ensuring that our programs, services, staff and board of directors are accountable to the individuals we serve. Methods of curing concrete structures and their comparisons.
This study considered the effect of different methods of curing on density and compressive strength of concrete. Solid grounding a power system is said to be effectively grounded or solidly grounded when the neutral of a generator, power transformer or grounding transformer are directly connected to the ground through a conductor of negligible resistance and reactance. Curing begins immediately after placement and finishing so. Conductors typical conductor types include flat tape, solid circular and stranded cable. A good ground reduces the probability of equipment damage due to voltage transients, but by no means eliminates it. Spraying of a liquid, membraneforming curing compound is a commonly used curing method. One of the first 3d printing techniques is solid ground curing or sgc. In this step, cad model issolid ground curing sgc is a photopolymerbased additive manufacturing or 3d printing as the basis of. Influence of post curing conditions on the mechanical. The photo mask from mask generator is placed in close proximity above the work piece and aligned under a collimated uv lamp. These techniques are especially useful in the prefabrication industry, wherein high early age strength enables the removal of the formwork within 24 hours, thereby reducing the cycle time, resulting in costsaving benefits. Creates a translucent, frost, pebblelike finish that emulates the look of real seaglass. Paint is permanent after air drying 21 days or can be baked to expedite permanence.
217 636 254 888 1365 443 1437 928 1432 292 35 459 969 811 198 1013 1009 987 227 828 652 742 576 88 923 558 1206 1464 261 142 1099 1183