Abstract: A cement repair composition is provided for repairing thin concrete. The composition comprises, in weight percentages: fine aggregates, 50-80%; Portland cement, 10-20%; reinforcing fibers such as polyethylene, steel and fiberglass fibers, 0-5%; and a plurality of further additives. The additives preferably include a lithium admixture, an air entraining admixture and a water reducing chemical additive, and a shrinkage compensating chemical additive, in a combined weight percentage of 0.01 to 5%.

Abstract: A method is provided for enabling an infrastructure, such as pipework or a bundle of electrical cables, to be passed directly through a wooden structural element without significantly weakening the structural element, rather than being routed around the structural element. A throughhole is provided in the structural element which extends between opposed sides. The method includes affixing to the wooden structural element a unitary reinforcement member including two spaced, parallel side plates joined together by a support plate. Each of the side plates has an opening therein as large as or larger than the throughhole. The reinforcement member is affixed to the wooden structural element by securing one of the side plates to each side of the structural element, with the opening of each of the side plates disposed so as to surround the throughhole.

Abstract: A method and apparatus are provided for performing non-contact inspection of large concrete structures such as dams. A phrased array acoustic source transmits an acoustic wave onto the concrete structure. A laser transmitter-receiver unit transmits a laser beam onto the surface of the structure such that the beam is modulated by the acoustic wave and reflected back to the receiver portion of the unit. The acoustic wave will be distorted by defects or anomalies in the concrete structure and this will affect the signal content of the received laser beam. The laser beam is ultimately converted into a two-dimensional image or a three-dimensional tomographic image for further processing.

Abstract: A method is provided for enabling an infrastructure, such as pipework or a bundle of electrical cables, to be passed directly through a wooden structural element without significantly weakening the structural element, rather than being routed around the structural element. A throughhole is provided in the structural element which extends between opposed sides. The method includes affixing to the wooden structural element a unitary reinforcement member including two spaced, parallel side plates joined together by a support plate. Each of the side plates has an opening therein as large as or larger than the throughhole. The reinforcement member is affixed to the wooden structural element by securing one of the side plates to each side of the structural element, with the opening of each of the side plates disposed so as to surround the throughhole.

Abstract: A cement repair material composition is provided for repairing thin concrete. The composition comprises, in weight percentages: fine aggregates, 50-80%; cement, 10-20%, said cement being selected from the group consisting of expansive hydraulic cement, gypsum cement, and magnesium phosphate cement; reinforcing fibers such as polyethylene, steel and fiberglass fibers, 1-5%; and a first water-reducing chemical additive, and a second shrinkage compensating chemical additive, a combined 0.01 to 5%.

Abstract: The present invention is an economical and easily installed irrigation system for agricultural products covering large areas. The invention comprises top and bottom layers of geosynthetic material having a non-cohesive, porous material between the layers. A water distribution system is also placed between the layers. This system can be placed directly on the area to be irrigated without digging a trench or hole. Agricultural products, such as turf or row crops, are placed with top soil directly on the system.

Abstract: A cement mixture is provided for preventing or reducing the formation of micro-cracks during hydration. The cement mixture includes both a conventional cement and a cement micro-encapsulated in a time-release polymer coating. The micro-encapsulated cement does not hydrate until a few hours to a few days after the bulk of the conventional cement has hydrated, thereby allowing for autogenous healing of small cracks.

Abstract: A material provided for sealing leaks in water conveyance systems includes a porous hydrophilic rubber impregnated with a water reactive polyurethane resin. When the material comes into contact with water, the rubber and polyurethane swell and this results in increased adhesion and improved sealing.

Abstract: A cement mixture is provided for preventing or reducing the formation of micro-cracks during hydration. The cement mixture includes both a conventional cement and a cement micro-encapsulated in a time-release polymer coating. The micro-encapsulated cement does not hydrate until a few hours to a few days after the bulk of the conventional cement has hydrated, thereby allowing for autogenous healing of small cracks.

Abstract: A method and apparatus are provided for performing non-contact inspection of large concrete structures such as dams. A phrased array acoustic source transmits an acoustic wave onto the concrete structure. A laser transmitter-receiver unit transmits a laser beam onto the surface of the structure such that the beam is modulated by the acoustic wave and reflected back to the receiver portion of the unit. The acoustic wave will be distorted by defects or anomalies in the concrete structure and this will affect the signal content of the received laser beam. The laser beam is ultimately converted into a two-dimensional image or a three-dimensional tomographic image for further processing.

Abstract: A method and system are provided for detecting a void in backfill material such as soil surrounding a buried conduit such as a pipeline. The void is detected by monitoring an acoustic response from the conduit in response to acoustic excitation of the interior of the conduit. An analysis of changes in the acoustic response is then related to the presence or absence of a void in the backfill material.

Abstract: An acoustic travel time tomography system enables determining of physical properties of a dam, or a like concrete mass. The system includes a plurality of acoustic sensors, positioned on the dam at a plurality of spaced sensor locations which are known relative to each other, for producing output data responsive to the detection thereby of acoustic waves generated in the dam. An impact source produces an impact at an impact location which is known relative to the sensor locations so as to generate acoustic waves in the dam for detection by the sensors. A data processing unit acquires output data from the sensors produced responsive to acoustic waves generated by the impact source and analyzes this output data, together with data related to the relative locations of the sensors and the impact source, to determine physical properties of the dam.