Voids repair

Type 1 slurry surfacing is suitable to seal cracks, fill voids, repair moderate surface distresses (surface erosion) and provide protection. 

Vacuum bag bonding is restricted by definition to less than 1 atm (<15 psi) which can be insufficient to achieve good part contact and prevent bondline voids. Hence vacuum bag bonding is rarely used outside of repair situations. 

One of the most desirable aspects of plastics and composites is the ability to make net-shaped parts. The same process that creates the material also creates the structure. The penalty for this advantage is that the process of curing a thermosetting plastic or composite part is irreversible. Any part that is not properly processed represents a loss of part, material and the money and time required to make that part, although larger parts are usually repaired if possible. Proper shape becomes a controlled property in addition to the bulk material properties, such as mechanical (stiffness or strength), physical (density, void content, etc.), chemical (degree of cure or carbonization, chemical resistance), electrical (resistivity, conductivity), or any combination of these. 

Base deletions in DNA are common lesions and are also routinely introduced as an intermediate in the course of the repair of other types of lesions. The structural void and resulting flexibility has been suggested as a target for recognition by repair enzymes [3]. We looked for evidence of additional dynamics associated with abasic lesions by measuring the... 

Major causes for coating failure are surface cracking and undetected pinholes or voids. These can be repaired and serious problems avoided. Coatings generally fail in different modes, these are chemical failure, abrasion failure, adhesive failure, cohesive failure and undercoat corrosion. For performance evaluation of coatings on experimental basis on these parameters various ASTM and BS specifications are presently being used. 

The sealant used to finish filling the joint should end flush with the surface. If there is any "overpour," it should be left until cured, then cut off with a razor blade, trimming it down to the plane of the floor surface. There should be no air bubbles, nor voids. If any appear, they should be opened up and repaired in the manner recommended by the manufacturer of the material. 

In addition, this system has been modified by adding dibenzyl sorbitol to give high thixotropicity to the system to prevent penetration of the system into foam cells. For these reasons the foam system is very suitable for pour-in-place application into small foam voids, e.g., 1 to 10 cm, for repairing surface air voids of molded automotive-foam seats to reduce the rejection rate, thereby resulting in lowering production costs. 

Heretofore, the most commonly used method of repairing cracks in concrete was by injection of a cement slurry grout. It is obvious that such a grout, based on a cementitious composition, would shrink and not fill the void completely. it is also highly likely that such a grout, after curing, v/ould crack again at the same stress points. 

There is no true remedy for a collapsed bed, only prevention. Some authors suggest the repair of a column by filling the void with additional packing or glass beads. I do not recommend this, since in nearly all cases the problem is only partially remedied, and the performance of the column after such a repair is nowhere close to the performance of a new column. This is espec y undesirable in a validated environment. 

Even if the principal cause of corrosion is carbonation or chloride penetration, construction defects (voids, honeycombs, early cracks, etc.) or other processes of deterioration (sulfate, freeze-thaw, dynamic loading, etc.) can contribute to the damage of the structure. These should be detected in order to take appropriate measures in the repair work. Furthermore, the condition of the structure with regard to stability must be investigated in order to define if strengthening is required. 

Amino alcohols are ambiodic, forming a film on the steel surface, blocking both anodic and cathodic reactions. They can be applied as a coating on the surface of the concrete, a plug of material in a hole, admixed into repairs. The supplier claim that these materials will move very rapidly through the air voids in the concrete, through pores and microcracks to reach the steel and protect it. 

PTFE barriers were completely repaired with bone tissue, whereas incomplete lamellar bone formation was detected in defects treated with Gengiflex membranes, resulting in voids and lack of continuity of bone deposition. This demonstrated that the non-porous PTFE barrier is a more effective alternative to treat osseous defects than a bacterial cellulose membrane. 

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