ASTM C151 Cement Autoclave
The Cement Autoclave accelerates curing of mortar bar specimens in controlled steam pressure and temperature to determine autoclave expansion of hydraulic cements by ASTM C151 method. The ASTM method for autoclave expansion evaluates the potential delayed expansion caused by the hydration of the cement. The ASME certified welded steel cylinder has a bolted cover and is mounted on a rugged frame inside a heat insulated metal housing. Operating pressures are maintained automatically by the regulator from 60—350psi (0.4—2.4MPa) and displayed on the 600psi x 5psi dial gauge with 4.5in (115mm) diameter. A 350psi safety pop valve is included. An ASTM 2F thermometer, air vent valve, wrench and package of five gaskets are included. Replacement Gaskets, Test Bar Holder, ASTM Thermometer and Safety Pop Valves are available as accessories.
115V/50-60Hz 15.7 amps max power demand. For 230V service order 3,000W Step-Up/Step-Down Transformer.
Features:
-
ASME Certified welded steel cylinder with bolted cover
-
Rugged frame and heat insulated metal housing
-
Operating pressure from 60—350psi
-
350psi safety pop valve set
-
2-Year warranty
Included Items:
-
Cement Autoclave
-
ASTM 2F Thermometer
-
Wrench
-
5 Gaskets
-
Safety Pop Valve Calibration Certificate
Pressure Rating 60–350psi (0.4–2.4bar)
Electrical 115V / 50-60Hz, 18W, 15A
Chamber Dimensions 6.1 x 16in (156 x 407mm), Dia.xH
Product Dimensions 17 x 48 x 28in (432 x 1220 x 711mm), WxDxH
Meets Test Methods: AASHTO M210 AASHTO T107 ASTM C 151 ASTM C 490
What is a Cement Autoclave
The autoclave expansion test provides an index of potential delayed and critical test for evaluating the potential delayed expansion of hydraulic cement which can be caused by the hydration of CaO or MgO or both. This test is necessary to determine the expansion of a hardened cement paste when exposed to autoclave conditions. The autoclave expansion of hydraulic cement test is widely used in the construction site industry to ensure the quality and performance of hydraulic cement. By simulating the conditions that cement may face in real world applications this test helps to identify any potential issues that may arise from the expansion of hydraulic cement so that the durability and reliability of concrete structures can be ensured.
Properties of Hydraulic Cement
Hydraulic cement is a cement that hardens when exposed to water and its properties are critical in determining its autoclave expansion. The expansion of hydraulic cement is influenced by many factors including the type and amount of MgO present in hydraulic cement, clinker cooling rate and hydration rate. Understanding these properties is necessary to determine the autoclave expansion and to ensure the cement is suitable for use in concrete structures. For example a higher MgO content can cause more expansion which may not be desirable in some applications. So careful control and assessment of these properties is necessary to produce good quality hydraulic cement.
Test Specimens and Preparation
The test specimens used in the autoclave expansion test are paste prisms 25 × 25 × 280mm with 250mm gauge length. These prisms are cast with a specific water to cementitious materials ratio to ensure consistency and repeatability of the test results. The preparation of the test specimens follows a standard test method for autoclave expansion which is essential to get accurate and reliable results. Proper preparation involves mixing the materials thoroughly, casting the prisms in molds and curing them under controlled conditions before the autoclave test. This process ensures that the test specimens represents the properties of the hydraulic cement being tested.
Autoclave Testing Procedure
The autoclave testing procedure involves exposing the test specimens to high pressure and temperature conditions 2.07 MPa and 204°C for 3 hours. During this time the specimens undergo significant stress simulating the conditions they may face in real concrete structures. The expansion of the specimens is measured before and after the autoclave test and the results are used to determine the autoclave expansion of the hydraulic cement. This test method is designed to give a clear indication of how the cement will perform under extreme conditions so that only the best materials are used in construction site projects.
Industry Applications of Autoclave Testing
Autoclave testing has many industry applications including to evaluate the expansion of cement in concrete which can cause cracking and other problems. The test is used to determine the suitability of hydraulic cement for use in concrete structures like buildings, bridges and dams. Autoclave testing is also used to develop new cement products and to improve the performance of existing ones. The results of the autoclave expansion test is used to ensure the quality and performance of hydraulic cement which is critical in construction site industry. By identifying the problem early autoclave testing helps in preventing costly repairs and ensuring the longevity and safety of concrete structures.