AASHTO M85-20 pdf free download
AASHTO M85-20 pdf free download.Portland Cement.
5.1.3. Limestone- The amount shall be not more than 5.0 percent by mass such that the chemical and physical requirements of this standard are met (see Note 4). The limestone, defined in ASTM C51, shall be naturally occurring and consist of at least 70 percent by mass of one or more of the mineral forms of calcium carbonate. If limestone is used, the manufacturer shall report the amount used, expressed as a percentage of cement mass, as determined using Annex B, along with the oxide composition of the limestone. Note 3- This standard permits portland cement to contain limestone, but does not require that limestone be an ingredient in the cement. Cement without ground limestone can be specified in the contract or order. 5.1.4. Inorganic Processing Additions- The amount shall not be more than 5.0 percent by mass of cement. Not more than one inorganic processing addition shall be used at a time. For amounts greater than 1.0 percent, they shall have been shown to meet the requirements of M 327 for inorganic processing additions in the amount used or greater. If an inorganic processing addition is used, the manufacturer shall report the amount used, expressed as a percentage of cement mass, along with the oxide composition of the processing addition (see Note 5). Note 4 -These requirements are based on data and recommendations by Taylor.’ 5.1.5. Organic Processing Additions- These additions shall have been shown to meet the requirements of M 327 in the amounts used or greater, and the total amount of organic processing additions used shall not exceed 1.0 percent of the weight of portland cement clinker. 5.1.6. Air- Entraining Addition (for Air Entraining Portland Cement Only)- -The interground addition shall conform to the requirements of ASTM C226.
6. CHEMICAL COMPOSITION 6.1. Portland cement of each of the ten types shown in Section 1 shall conform to the respective standard chemical requirements prescribed in Table 1. In addition, optional chemical requirements are shown in Table 2. Note 5- -The standard composition requirements in Table 1 require reporting of equivalent alkalis. Cements with a maximum of 0.60 percent equivalent alkalis were historically designated as“low-alkali cements” and recommended for use with aggregates susceptible to alkali- silica reaction (ASR). However, low-alkali cements (in the absence of other mitigation measures) may not be effective in mitigating ASR. Guidance on formulating concrete mixtures, including calculating alkali loading using equivalent alkali content of cement to minimize the potential for ASR, is provided in R 80. Note 6- The limit on the sum, C3S + 4.75C3A, in Table 1 provides control on the heat of hydration of the cement and is consistent with an ASTM C1702 3-day heat of hydration limit of 315 kJ/kg (75 cal/g). Note 7- -There are cases where performance of a cement is improved with SO3 in excess of the Table 1 limits in this specification. ASTM C563 is one of several methods a manufacturer can use to evaluate the effect of sulfate content on cement characteristics. W henever SO3 content of a cement exceeds Table 1 limits, ASTM C1038/C 1038M results provide evidence that excessive expansion does not occur at this higher sulfate content.AASHTO M85-20 pdf download.
