RCC Pile

  1. Objective Carbonation of concrete is a process by which Carbon di Oxide from the air penetrates into the concrete and reacts with calcium hydro-oxide to form calcium carbonates. Conversion of Ca(OH) 2  into CaCO 3  by action of CO 2  by itself is not reactive. In the presence of moisture, CO 2  changes into dilute carbonic acid which attacks the reinforcement and also reduces alkalinity of concrete. In this test Phenolphthalein solution is used as indicator. 2. Application Carbonation of concrete is one of the main reasons for corrosion of reinforcement. Oxygen and moisture are the other components required for corrosion of embedded steel. In this test, the depth of carbonation is determined. The rate of carbonation depends on the grade of concrete, permeability of concrete, whether the concrete is protected or not, depth of cover, time, etc. Fig. 1  : Carbonation Test on Concrete 3. Procedure This test is most commonly carried out by spraying the indi...

  Magnetic Particle Testing (MPT) , also referred to as Magnetic Particle Inspection, is a   nondestructive examination (NDE)   technique used to detect surface and slightly subsurface flaws in most ferromagnetic materials such as iron, nickel, and cobalt, and some of their alloys. Because it does not necessitate the degree of surface preparation required by other nondestructive test methods, conducting MPT is relatively fast and easy. This has made it one of the more commonly utilized NDE techniques. FREE RESOURCE:   Click here to download a detailed overview of Magnetic Particle Testing. MPT is a fairly simple process with two variations: Wet Magnetic Particle Testing (WMPT) and Dry Magnetic Particle Testing (DMPT). In either one, the process begins by running a magnetic current through the component. Any  cracks or defects  in the material will interrupt the flow of current and will cause magnetism to spread out from them. This will create a “flux leakag...

  1. Objective Liquid penetrant processes are non-destructive testing methods for detecting discontinuities that are open to surface. They may be effectively used in the inspection of both ferrous and non-ferrous metals and on non-porous, non-metallic materials, such as ceramics, plastics and glass. Surface discontinuities, such as cracks, seams, laps, cold shuts and laminations, are indicated by these methods. Flaw detection with the help of liquid penetrant is being increasingly used in various industries in the country and recommendations of a general character providing guidance on the applications of these methods are considered necessary. 2. Apparatus Required Fig. 1: Surface Cleanser, Developer and Penetrant 3. Reference IS 3658:1999 Code of Practice for Liquid Penetration Flaw Detection (second revision). Reaffirmed- May 2014. 4. Principle Of Test ·   A suitable liquid penetrant is applied to the surface of the component under examination and is permitt...

  Corrosion is a natural process that occurs when a structure is exposed to elements like CO2 or chloride, which can penetrate the concrete all the way to the steel reinforcement. This can have serious durability and safety consequences, which is why it is important to monitor corrosion using an accurate and trusted method. The half-cell potential test is the only corrosion monitoring technique standardized in  ASTM C876 – 15 : Standard Test Method for Corrosion Potentials of Uncoated Reinforcing Steel in Concrete. It is used to determine the probability of corrosion within the rebar in reinforced concrete structures. This blog dives into the specifics of concrete corrosion, the half-cell potential technique for testing concrete corrosion, and the ways in which the data from the half-cell potential test can be interpreted. The Basics of Concrete Corrosion In reinforced concrete structures, there is a natural protective film that forms on the surface and prevents the bar from c...

  The fundamental principle behind pull out testing is that the test equipment designed to a specific geometry will produce results (pull-out forces) that closely correlate to the compressive strength of concrete. This correlation is achieved by measuring the force required to pull a steel disc or ring, embedded in fresh concrete, against a circular counter pressure placed on the concrete surface concentric with the disc/ring. Types of Pull Out Tests: Depending upon the placement of disc/ring in he fresh concrete, pull out test can be divided into 2 types,  LOK test CAPO test  (Cut and Pull out Test)  LOK Test: The LOK-TEST system is used to obtain a reliable estimate of the in-place strength of concrete in newly cast structures in accordance with the pullout test method described in ASTM C900, BS 1881:207, or EN 12504-3. LOK Test A steel disc, 25 mm in diameter at a depth of 25 mm, is pulled centrally against a 55 mm diameter counter pressure ring bearing ...

  The  Windsor Probe test  was developed in the mid-1960s in a joint effort between the New York Port Authority and the  Windsor  Machine Company. It is a penetration resistance  test  based on the surface hardness of a concrete element WINDSOR PROBE TESTING – GETTING “CONCRETE” RESULTS Whether cast-in-place, pre-cast, reinforced or unreinforced, concrete is the most-widely used construction material in the world. Detroit’s resurgence has led to repurposing of old warehouses and other legacy buildings. Many of these structures have been neglected without routine maintenance for many years, and subjected to non-climate controlled conditions. Consequently, concrete structural members have experienced significant deterioration, as shown below. Concrete spall near the base of a column exposing embedded, corroded reinforcing steel. Original design reference documents containing information about construction materials are often no longer available for these...

  CORROSION TESTING STANDING UP TO ENVIRONMENTAL CONDITIONS Corrosion Testing  determines the resistance of materials to corrosion under certain environmental conditions, including temperature, humidity and salt water. Laboratory Testing Inc. offers a full array of corrosion testing services at our Philadelphia, PA (USA) area facility to ensure the performance of metals, platings and coatings. A wide-range of ASTM Corrosion Testing is provided, including the ASTM B117 Salt Spray Test. Many additional corrosion testing services are available and performed to industry specifications. CORROSION TESTING LTI offers Accelerated Intergranular Corrosion Testing to detect corrosion susceptibility in a relatively short period of time. The corrosion testing lab is just as helpful in identifying corrodents and environmental factors responsible for corrosion problems with products in service. Our Corrosion Testing capabilities are enhanced with an SEM/EDS system fo...