Method and device for evaluating quality of concrete structures
AssigneeSinotech Engineering Consultants, Inc.
InventorsYiching Lin, Chiafeng Chang
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Abstract
An evaluation device and an evaluation method for detecting quality of concrete structures comprising a conductive impact device, a sensing film, a receiver, an operation device and an auxiliary circuit, the device and the method is characterized by calculating a penetration time of the conductive film before measuring the depth of a crack in the concrete, and the evaluation work which conventionally requires dual receivers only needs now a single receiver for completion of the work. Therefore, cost and works for evaluation and signal analysis are reduced; this largely enhances the evaluation efficiency and technical level.
Claims4
An apparatus for detecting quality of concrete structures, comprising:
- a conductive impact device including a connecting section with a predetermined length, said connecting section having one end formed with an impacting end and the other end formed with a knob;
- a sensing film including a conductive film and a non-conductive plastic film stuck at a point to be impacted;
- a receiver for receiving signals introduced by longitudinal waves, transverse waves and Raleigh's waves;
- an operation device including an analog-to-digital interface card for receiving signals from a first wire connected to said connecting section, a second wire connected to said receiver, and a third wire connected to said conductive film for calculating the depth of a crack;
- and
- an auxiliary circuit including a resistant connected between said first and third wires, and an electric power source connected in serial with said third wire;
- wherein when said conductive impact device is in contact with said conductive film, said first wire is connected with said third wire through said connecting section to form a closed circuit from an open circuit.
A method for detecting quality of concrete structures, comprising the steps of:
- preparing a receiver and performing two impact tests at different positions to get two sets of data for calculating a penetration time τ and speed of longitudinal P waves (CP);
- performing an evaluation test at an impact point and determining a first distance H1 between said impact point and a crack and a second distance H2 between said impact point and the receiver;
- measuring an occurring time t1 of a source of waves from a transient reacting waveform induced by said evaluation test, and a time t2 of the arrival of P diffraction waves at the receiver via a tip of said cracl;
- obtaining a value of Δt after impact by means of a formula Δt=t2−t1−τ;
- and
- substituting CP, Δt, H1 and H2 in the following formula to obtain the value of depth d of said crack, d = [ ( C P × Δ t ) 2 + H 1 2 - H 2 2 2 × C P × Δ t ] 2 - H 1 2 .
Dependencies are inferred from the claim text.