AASHTO R71-16 pdf free download
AASHTO R71-16 pdf free download.Sampling and Amount of Testing of Hydraulic Cement.
4. SIGNIFICANCE AND USE
4.1. The sampling procedures described are intended for use in the procurement of samples of hydraulic cement after it has been manufactured and is ready to be offered for sale. They are not intended as sampling procedures for quality control purposes during manufacturing. The testing procedures outlined cover the amount of testing to be done and provide guidance for reporting on conformance or nonconformance of cements with requirements of purchase specifications.
4.2. This practice is referenced as the procedure for sampling natural cement (ASTM ClO/C1OM), masonry cement (ASTM C91/C9 I M), portland cement (M 85), blended hydraulic cement (M 240M/M 240), expansive hydraulic cement (ASTM C845/C845M), plastic (stucco) cement (ASTM C1328), mortar cement (ASTM C1329), and hydraulic cement (ASTM Cl 157/Cl l57M) based on a performance specification.
4.3. Most building codes and construction specifications require that hydraulic cement to be used in the work meet the applicable requirements of the relevant purchase specifications, such as Specifications M 85, M 240M/M 240, ASTM C9 I /C9 I M, ASTM C845/C845M, ASTM Cl 157/Cl 1 57M, ASTM Cl 328, and ASTM Cl 329. If the code or specification requires sampling of the manufactured cement, the provisions given in Section 4.4 are applicable. Not much cement is sold on the basis of such sampling and testing. A useful discussion of sampling and testing cement is contained in ACI 225.1 R.
4.4. The procedures covered in this practice should be done by or for purchasers of hydraulic cement who are using a code or specification that requires sampling and testing to determine if the samples conform to the relevant acceptance specifications. The testing is done using specified methods to determine whether the samples yield test results that conform to the specification, and the tests serve as a basis for acceptance or rejection of the lot of material sampled.
4.5. It is neither intended nor required that all cements he tested using all the test methods referenced in Section 2.
5. KINDS AND SIZE OF SAMPLES AND BY WHOM TAKEN
5.1. A cement sample secured from a conveyor, bulk storage, or a bulk shipment in one operation shall be termed a “grab sample.” A sample obtained during a 10-mm interval using an automatic sampling device that continuously samples a cement stream may also be considered a grab sample. Grab samples taken at prescribed intervals over a period of time may be combined to form a “composite sample” representative of the cement produced during that period of time.
5.2. All samples, whether grab or composite, shall have a mass of at least 5 kg [10 lb].
5.3. The purchaser may designate a representative to supervise the sampling, packing, and shipping of samples when it is so specified in the purchase contract.
5.4. Package the samples in moisture-proof, airtight containers numbered consecutively in the order in which the samples are taken (see Note I). The purchase contract shall state who will pay for the costs of sampling, packaging, shipping, and testing the samples.
Note 1- Polyvinyl chloride sample containers, upon occasion, have been found to affect the air-entraining potential of a cement sample. The same problem might be experienced with containers made from other plastics.AASHTO R71-16 pdf download.
