PHYSICAL CEMENt TESTS.pdf

PREPARED BY: ENGR. AIZA C. CALLA DPWH Albay 1st DEO  The purpose of this test method is to determine whether or not the hydraulic cement under test meets the air-entraining or non air-entraining requirements of the applicable hydraulic cement specification for which the test is being made. Mai...

PREPARED BY: ENGR. AIZA C. CALLA DPWH Albay 1st DEO  The purpose of this test method is to determine whether or not the hydraulic cement under test meets the air-entraining or non air-entraining requirements of the applicable hydraulic cement specification for which the test is being made. Maintain the temperature of the room and dry materials at 23.0 ± 4.0°C. Condition the mixing water and the measure, if it is being calibrated at 23 ± 2°C. Maintain the relative humidity of the laboratory at not less than 50 %.  CYLINDRICAL MEASURE A cylindrical measure having an inside diameter of 76 ± 2 mm, a depth (approximately 88 mm) and Volume 400 ± 1 mL FLOW TABLE AND FLOW MOLD The mold has a top diameter of 2.75 inches and a bottom diameter of 4 inches. STRAIGHTEDGE -a steel straightedge not less than 200 mm long and not less than 1.5 mm nor more than 3.5 mm in thickness. MIXER, BOWL, AND PADDLE -an electrically driven mechanical mixer of the type equipped with paddle and mixing bowl. SLOW SPEED = 140±5 rpm MEDIUM SPEED = 285±10 rpm WEIGHTS AND WEIGHING DEVICES TROWEL  GLASS GRADUATES TAMPER  TAPPING STICK -a piece of hard wood having a diameter of approximately 16 mm and a length of approximately 152 mm. SPOON  Batch Proportion: Weigh cement and sand (20-30 Required Flow: 87.5% ± 7.5% standard sand) using balance. Cement – 350 g Prepare water using graduated Sand – 1400 g Required diameter of flow: cylinder. Water – Determined by Flow Test, 7.2’’-7.8’’ or 19-23 units regardless of the type of cement (Distilled Water) FOR MIXING OF MORTAR Start the mixer at slow speed, then add cement to the bowl for 30 Place all the mixing water in the bowl. (Initially use 250ml water.) seconds. NEXT PAGE  Add the entire quantity of sand Stop the mixer and let the mortar slowly over a 30 seconds period, Change to medium speed for 30 stand for 90 seconds. During the while mixing at slow speed. seconds. first 15 seconds of this interval, quickly scrape down into the batch any mortar that may have collected on the side of the bowl. FOR FLOW DETERMINATION Finish mixing for 60 seconds at medium speed. Carefully wipe the flow table clean and dry, and place the flow mold at the center. NEXT PAGE  Fill the mold with 2 layers of Cut off the mortar to a plane mortar and tamp 20 times each surface flush with the top of the Wipe the table top clean and dry, layer. (19 tamps near the perimeter mold by drawing the straightedge being especially careful to remove and 1 tamp at the center) or the edge of the trowel with a any water from around the edge of sawing motion across the top of the the flow mold. mold. Lift the mold away from the mortar Immediately drop the table 10 1 min after completing the mixing operation. times in 6 s. Measure the diameter of mortar NEXT PAGE on 4 sides. FOR DETERMINATION OF 400 ML After the measure has been filled MASS OF MORTAR and tamped in the above prescribed Tamp each layer 20 times around manner, tap the sides of the measure the inner surface of the measure. lightly with the side of the tapping Weigh the cylindrical measure. For the final layer of mortar, overfill Using the spoon, place the mortar stick. One each at five different the 400 mL measure approximately points at approximately equal gently into the 400 ml measure in 3 20 mm. spacing around the outside of the equal layers. measure, in order to preclude entrapment of extraneous air. Then cut the mortar off to a plane surface, flush with the top of the measure, by drawing the Wipe off all mortar and water straightedge with a sawing motion adhering to the outside of the Determine the mass of the across the top of the measure, measure. measure and mortar. making two passes over the entire surface, the second pass being made at right angles to the first. TYPE 1 = 12% MAXIMUM TYPE 1P = 12% MAXIMUM  This test method provides a means of determining the compressive strength of hydraulic cement and other mortars and results may be used to determine compliance with specifications.  The temperature of the air in the vicinity of the mixing slab, the dry materials, molds, base plates, and mixing bowl, shall be maintained between 23.0 ± 3.0°C. The temperature of the mixing water, moist closet or moist room, and water in the storage tank shall be set at 23 ± 2°C. Maintain the relative humidity of the laboratory at not less than 50 %.  SPECIMEN MOLDS (2-in cube) FLOW TABLE AND FLOW MOLD The mold has a top diameter of 2.75 inches and a bottom diameter of 4 inches. THERMO HYGROMETER - a measuring device for orienting measurement of temperature and relative humidity. MIXER, BOWL, AND PADDLE -an electrically driven mechanical mixer of the type equipped with paddle and mixing bowl. SLOW SPEED = 140±5 rpm MEDIUM SPEED = 285±10 rpm  MOIST CABINET CURING TANK WEIGHTS AND WEIGHING DEVICES TROWEL  GLASS GRADUATES TAMPER  NUMBER OF SPECIMENS 6 9 12 Weigh cement and sand (graded Cement, g 500 740 1060 standard sand/ottawa sand) using balance. Prepare water using Sand, g (1 part of cement: 2.75 parts of sand) 1375 2035 2915 graduated cylinder. Water (distilled), ml (0.485 water-cement ratio if Type 1 242 359 514 Cement) If Type 1P Cement, compute the amount of water. Required diameter of flow: 8.2’’-8.6’’ or 25-28 units NEXT PAGE Required Flow: 110% ± 5%  FOR MIXING OF MORTAR Start the mixer at slow speed, then Add the entire quantity of sand Place all the mixing water in the add cement to the bowl for 30 slowly over a 30 seconds period, bowl. (Initially use 250ml water.) seconds. while mixing at slow speed. Stop the mixer and let the mortar stand for 90 seconds. During the Change to medium speed for 30 seconds. first 15 seconds of this interval, quickly scrape down into the batch NEXT PAGE any mortar that may have collected on the side of the bowl.  FOR FLOW DETERMINATION Finish mixing for 60 seconds at Fill the mold with 2 layers of medium speed. Carefully wipe the flow table clean mortar and tamp 20 times each and dry, and place the flow mold at layer. (19 tamps near the perimeter the center. and 1 tamp at the center) Cut off the mortar to a plane surface flush with the top of the Wipe the table top clean and dry, mold by drawing the straightedge or the edge of the trowel with a being especially careful to remove any water from around the edge of NEXT PAGE sawing motion across the top of the the flow mold. mold.  FOR MOLDING OF SPECIMEN Lift the mold away from the Immediately drop the table 25 Prepare the three-gang mold and mortar 1 min after completing the times in 15 s. apply greasing agent (oil) to the mixing operation. Measure the diameter of mortar on interior faces and bases of the 4 sides. molds. Tamp the mortar in each cube compartment 32 times in about 10 s in 4 rounds each layer, each Using the spoon, fill the mold with 2 layers of mortar. round to be at right angles to the other and consisting of eight NEXT PAGE adjoining strokes over the surface of the specimen.  Bring in the mortar that has been Then, for the purpose of leveling the forced out onto the tops of the molds mortar and making the mortar that Cut off the mortar to a plane surface with a trowel and smooth off the protrudes above the top of the mold flush with the top of the mold by cubes by drawing the flat side of the of more uniform thickness, draw the drawing the straight edge of the trowel (with the leading edge slightly flat side of the trowel (with the trowel (held nearly perpendicular to raised) once across the top of each leading edge slightly raised) lightly the mold) with a sawing motion over cube at right angles to the length of once along the length of the mold. the length of the mold. the mold. FOR STORAGE OF SPECIMEN If the specimens are removed from Immediately upon completion of the molds before 24 h, keep them on molding, place the test specimens in the the shelves of the moist closet or moist moist closet or moist room. Keep all test room until they are 24-h old, and then specimens, immediately after molding, in the molds on the base plates in the immerse the specimens, except those for the 24-h test, in saturated lime NEXT PAGE moist closet or moist room from 20 to 72 water in storage tanks constructed of h with their upper surfaces exposed to noncorroding materials. Keep the the moist air but protected from storage water clean by changing as dripping water. required.  FOR DETERMINATION OF COMPRESSIVE STRENGTH Test the specimens immediately after their removal from the moist closet in the case of 24-h specimens, and from storage water in the case of all other specimens. All test specimens for a given test age shall be broken within the permissible tolerance prescribed as follows: If more than one specimen at a time is removed from the moist closet for the Apply the load rate at a relative 24-h tests, keep these specimens Wipe each specimen to a surface- rate of movement between the covered with a damp cloth until time of dry condition, and remove any upper and lower platens testing. If more than one specimen at a loose sand grains or incrustations corresponding to a loading on the time is removed from the storage water from the faces that will be in specimen with the range of 200- for testing, keep these specimens in water at a temperature of 23±2°C and of contact with the bearing blocks of 400 lbs/s (900-1800N/s). sufficient depth to completely immerse the testing machine. each specimen until time of testing.  The maximum permissible range between specimens from the same 1. Calculate the range (numerical mortar batch, at the same test age is 2. Calculate the average of the 8.7% of the average when three difference of the highest and lowest three values. cubes represent a test age and 7.6% value). when two cubes represent a test age. 4. Compare the results obtained from steps 1 and 3: a.) If the range is ≤ 8.7% of the average, consider the average of the three values 3. Calculate 8.7% of the average. is as the compressive strength (report to 5. Calculate the range of the two the nearest 0.1 MPa) remaining values. b.) If the range is > 8.7% of the average, discard the value which differs most from the average and proceed to step 5.  Compare the results obtained from steps 5 and 7: a.) If the range is ≤ 7.6% of the average, 6. Calculate the average of the two 7. Calculate 7.6% of the average. consider the average of the two values. remaining values as the compressive strength (report to the nearest 0.1mpa) b.) If the range is >7.6% of the average, make a retest of the sample. TEST AGE TYPE 1 TYPE 1P 3 DAYS 12 mpa minimum 13 mpa minimum 7 DAYS 19 mpa minimum 20 mpa minimum 28 DAYS 28 mpa minimum 25 mpa minimum  This test method is intended to be used to determine the amount of water required to prepare hydraulic cement pastes with normal consistency, as required for certain standard tests. Maintain the temperature of the room and dry materials at 23.0 ± 4.0°C. Condition the mixing water and the measure, if it is being calibrated at 23 ± 2°C. Maintain the relative humidity of the laboratory at not less than 50 %. VICAT APPARATUS  GLASS GRADUATES MIXER, BOWL, AND PADDLE -an electrically driven mechanical mixer of the type equipped with paddle and mixing bowl. SLOW SPEED = 140±5 rpm MEDIUM SPEED = 285±10 rpm WEIGHTS AND WEIGHING DEVICES TROWEL GLASS PLATE  MIXING OF PASTE Add the cement to the water and Prepare 650 g of cement. Place all the mixing water in the allow 30 s for the absorption of the Try 160 ml of water bowl. water. Stop the mixer for 15 s and during Start the mixer and mix at slow speed for 30 s. this time scrape down into the batch any paste that may have NEXT PAGE collected on sides of the bowl.  MOLDING TEST SPECIMEN Toss six times through a free Start the mixer at medium speed Quickly form the cement paste path of about 150 mm from one and mix for 60 s. into the approximate shape of a ball hand to another. with gloved hands. Press the ball, resting in the palm Remove the excess at the larger of one hand, into the larger end of the conical ring, completely filling end. Place the ring on its larger end on the base plate. NEXT PAGE the ring with paste.  Slice off the excess paste at the FOR CONSISTENCY smaller end at the top of the ring by DETERMINATION The plunger end shall be brought in a single oblique stroke of a sharp- contact with the surface of the edged trowel held at a slight angle Center the paste in the ring, paste, and tighten the set-screw. with the top of the ring, and resting on the plate, under the rod. smooth the top. Set the movable indicator to the Release the rod immediately at a upper zero mark of the scale. time not exceeding 30 s after completion of mixing.  Normal Consistency is reached once Apparatus shall be free of all vibrations the rod settles to a point 10 ± 1 mm below during the test. the original surface in 30 s after being released. Make trial pastes with varying percentages of water until the normal Make each trial with fresh cement. consistency is obtained. 25% - 35% NORMAL CONSISTENCY 10±1 MM PENETRATION (CONSISTENCY DETERMINATION)  This test method provides a means of determining compliance with a specification limit for Vicat time of setting. determine the time when a penetration of 25 mm is obtained. Vicat initial time of setting: time elapsed between the initial contact of cement and water and the time when the penetration is measured or calculated to be 25 mm. Maintain the temperature of the room and dry materials at 23.0 ± 4.0°C. Condition the mixing water and the measure, if it is being calibrated at 23 ± 2°C. Maintain the relative humidity of the laboratory at not less than 50 %. VICAT APPARATUS  GLASS GRADUATES MIXER, BOWL, AND PADDLE an electrically driven mechanical mixer of the type equipped with paddle and mixing bowl. SLOW SPEED = 140±5 rpm MEDIUM SPEED = 285±10 rpm WEIGHTS AND WEIGHING DEVICES TROWEL  GLASS PLATE MOIST CABINET Temperature: 23.0 ± 2.0°C Relative Humidity: not less than 95%  TIME OF SETTING Prepare the standard batch DETERMINATION (INITIAL TIME OF consisting of 650 g of cement and When the desired consistency is SETTING sufficient water to give a paste of attained proceed to Time of Setting normal consistency in accordance Test. Allow the time of setting specimen with the procedure described in to remain in the moist cabinet or Test Method C187. moist room for 30 min after molding without being disturbed. Determine the penetration of the 1-mm needle at this time and every Perform the penetration test by 15 min thereafter (every 10 min for Type III cements) until a lowering the needle of the rod until it rests on the surface of the cement NEXT PAGE penetration of 25mm or less is paste. obtained.  Release the rod quickly by Note: Tighten the setscrew, and the set releasing the set screw, and allow Make each penetration test at least the indicator, at the upper end of the needle to settle for 30 s; then 5 mm away from any previous the scale, or take an initial reading. take the reading to determine the penetration and at least 10 mm penetration. away from the inner side of the mold. TIME OF SETTING DETERMINATION Obtain verification measurements (FINAL TIME OF SETTING) within 90 s of the first “final set” Verify final set by performing two measurement. The elapsed time Determine the Vicat final time additional penetration between the initial contact of setting end point to be the first measurements on different areas of penetration measurement that does cement and water and the end the specimen surface. point determination above is the not mark the specimen surface with a complete circular impression. Vicat final time of setting. Note: Keep all the apparatus free from vibration during the penetration test. Keep the 1-mm needle straight and clean. The needle must be kept clean to prevent cement from adhering to the sides of the needle and decreasing penetration, and to prevent cement from adhering to the point and increasing penetration. TYPE 1: 45 – 375 MINS (INITIAL TIME OF SETTING) TYPE 1P: 45 MINS – 7 HRS (INITIAL TIME OF SETTING)  The autoclave expansion test provides an index of potential delayed expansion caused by the hydration of Calcium Oxide (CaO) or Magnesium Oxide (MgO), or both, when present in hydraulic cement. Maintain the temperature of the room and dry materials at 23.0 ± 4.0°C. Condition the mixing water and the measure, if it is being calibrated at 23 ± 2°C. Maintain the relative humidity of the laboratory at not less than 50 %.  GLASS GRADUATES MIXER, BOWL, AND PADDLE -an electrically driven mechanical mixer of the type equipped with paddle and mixing bowl. SLOW SPEED = 140±5 rpm MEDIUM SPEED = 285±10 rpm WEIGHTS AND WEIGHING DEVICES TROWEL MOLDS Molds shall have either one or two compartments. Molds for test specimens used in determining the length change of cement pastes and mortars shall provide for 25 by 25 by 285-mm prisms having a 250-mm gauge length. MOIST CABINET Temperature: 23.0 ± 2.0°C Relative Humidity: not less than 95% LENGTH COMPARATOR used for measuring length change of specimens AUTOCLAVE consisting of high-pressure steam vessel provided with a thermometer well. The autoclave shall be equipped with automatic controls and either a rupture disk with a bursting pressure of 2.4 Mpa (350 psi) ± 5 % or a safety valve that actuates at this pressure. In addition, the autoclave shall be equipped with a vent valve to allow the escape of air during the early part of the heating period and to release any steam pressure remaining at the end of the cooling period.  Note: Prepare the standard batch Both a time of setting specimen and consisting of 650 g of cement and an autoclave bar may be made from the same batch. If the paste to be used When the desired consistency is sufficient water to give a paste of for time of setting is the paste sample attained proceed to Autoclave normal consistency in accordance already used to determine normal Expansion Test. with the procedure described in consistency, then the autoclave bar Test Method C187. may be prepared immediately from the remainder of the batch. MOLDING TEST SPECIMEN Compact the top layer, cut off the paste flush with the top of the mold Immediately following preparation of the time with a thin-edged trowel, and of setting specimen or completion of mixing, mold the test specimen in two approximately equal layers, each layer being compacted with the thumbs or forefingers by pressing the smooth the surface with a few strokes of flat trowel. During the NEXT PAGE paste into the corners, around the gauge studs, operations of mixing and molding, and along the surface of the mold until a protect the hands with rubber homogenous specimen is obtained. gloves.  STORAGE OF SPECIMENS AUTOCLAVE EXPANSION After filling the mold, place it in the moist cabinet. Store the specimens in At 24 h ± 30 min after molding, Immediately obtain a length the molds in the moist enclosure for at remove the specimens from the comparator initial reading for each least 20 h; if removed from the molds moist atmosphere. specimen. before 24 h, they shall be kept in the moist closet or moist room until time of test. NOTE: The autoclave shall contain enough water, at an initial Place in the autoclave at room temperature of 20 to 28 °C (68 to 82 temperature in a rack so that all sides of the specimen will be exposed to saturated steam. °F), to maintain an atmosphere of saturated steam vapor during the NEXT PAGE entire test. Ordinarily, 7 to 10 % of the volume of the autoclave should be occupied by the water.  Close the valve and raise the To permit air to escape from the temperature at (216 ± 2 °C) of the At the end of the 3-h period, shut autoclave during the early portion autoclave at a rate that will bring off the heat supply and cool the of the heating period, leave the vent the gauge pressure of the steam to autoclave at such a rate that the valve open until steam begins to 2 Mpa (295 psi) in 45 to 75 min pressure will be less than 0.07 Mpa escape. from the time the heat is turned on. (10 psi) at the end of 1.5 h. Maintain the 2 ± 0.07 Mpa (295 ± 10 psi) pressure for 3 h. At the end of 1.5 h period, slowly release any remaining pressure by Cool the water surrounding the partially opening the vent valve bars at a uniform rate by adding until atmospheric pressure is attained. Then open the autoclave cold water so that the temperature of the water will be lowered to 23 °C NEXT PAGE and place the test specimen in in 15 min. water at a temperature above 90 °C. Maintain the water surrounding Remove one specimen at a time the specimens at 23 °C for an from the water, blot the pins, but Calculate the autoclave additional 15 min. not the specimen, and obtain a expansion. length comparator final reading. 0.8% MAXIMUM