Following are the six steps involved in designing a mix using the. Proper grading is important for concrete construction. Effect of continuous wellgraded combined aggregate grading. This research program was conducted at the nrmca research laboratory. Nominal coarse aggregate sizes for the particular tab selected will show up under the individual titles. In this lesson, you will be visiting your state or district laboratory to observe or perform basic tests. Improving concrete through optimizing aggregate gradation.
Bulking results in an increase in the volume of a given mass of sand caused by the films of water pushing the sand particles apart. Sieve analysis for dense gradation materials deleterious materials. Design the combined gradation to fit within the bands of the 8 18 percentretained chart. To determine if the empirical approaches lead to improved concrete performance such as lower paste content, lower shrinkage, higher strength, better workability etc. The focus of the website started out to advance aggregate proportioning through gradation, but has turned into much more than that. Earth and aggregate surfacing design guide technical note no. Also, a concrete repair class was developed with lecture notes and a video to help further fundamental topics of concrete repair and the materials used. The gradation of the hot mix will also determine the amount of liquid asphalt cement a. A listing of aggregate sources meeting the specified values for freezethaw dilation and absorption is available from the. We also have sieve shakers and material sample splitters for most applications. Concrete aggregate combined gradation example page 6 of 6 it is generally desirable to have at least at total of % of the combined aggregate retained on. State of illinois department of transportation bureau of.
The mixture aggregate technician shall be under the supervision of the aggregate technician or the agcs techn the aggregate ician. Achieving an optimized gradation generally requires the combination of at least three differently sized aggregates. Now, the focus has been to advance the knowledge of concrete materials, basic mixture design principles, and most importantly optimized graded concrete with gradation guidelines. This example presents some basic computations for optimizing a blend of multiple aggregates. Gradlab gds sieve analysis software for the quality control of construction aggregates, soils and asphalt paving materials gradlab gds gradation database system for aggregate quality control, asphalt quality control and soil grading records. Humboldts aggregate testing equipment includes astm testing sieves, as well as air jet sieves and wetwashing sieves. This spreadsheet is for educational and informational use only. Improper gradation will cause the rutting and cracking damage in pavement. Using theoretical and experimental particle packing for aggregate. The consensus, even among specifiers, seems to be that the 818 or 8. The gradation will be type ca2 as specified in table 1, aggregate gradation.
This workshop is intended to demonstrate the superpave asphalt mixture design system developed by the strategic highway research program shrp. Standard specifications section 424bituminous surface treatment b. Civl 37 18 gapgraded aggregate missing middle sizes no graintograin contact. Sieve analysis and fineness modulus sampling since the reason for sampling aggregates is to determine the gradation particle size of the aggregate, it is necessary that they be sampled correctly. A sieve analysis or gradation test is a practice or procedure used commonly used in civil engineering to assess the particle size distribution also called gradation of a granular material by allowing the material to pass through a series of sieves of progressively smaller mesh size and weighing the amount of material that is stopped by each sieve as a fraction of the whole mass. Chapter 2 sieve analysis and fineness modulus sampling. This is in contrast to most concretes, which typically contain two aggregates. Each chart represents one aspect of an optimized aggregate gradation. Development and implementation of aggregate grading for. Gradation measurement of asphalt mixture by xray ct.
All aggregate shall be the specified type, class, and grade, and shall meet the requirements for the intended use. In this rule, the percent retained on every sieve except the top and bottom two sieves should be between 8 and 18 percent. Note that the recommended distribution is actually between 8 and 22% retained for the smaller maximum size coarse aggregate used in this study. Aggregate gradation optimization literature search scholars mine.
Deviations in standard aggregate gradation and its. Grading is the particlesize distribution of an aggregate as determined by a sieve analysis using wire mesh sieves with square openings. Coarseness workability consolidation a new approach. Use aggregate meeting the requirements of section 70302 coarse aggregate, of the standard specifications. The nwg aggregates were developed by combining different proportions of size number 57 coarse aggregate and fine aggregates. Table i aggregate gradation sieve size general limits % passing 37. The 2d aggregate gradation from digital image segmentation procedure is transferred into 3d gradation by stereological method and the 3d gradation results are compared with the designed mixture gradation.
Aggregate voids content 5 figure 4 shows the cf chart and 8 18 chart results of blending different proportions of the no. One recommendation for combined aggregate specifies 100% passing the 38 inch sieve with from 20 to. Nominal maximum andor minimum sized stone in mix the nominal size distribution of an aggregate specification is defined as the range of sieve openings through which 100% of the aggregate can. The notes give information on the chemical makeup of aggregates, properties of aggregate, gradation, exacting aggregate, and using aggregates in applications. To determine if the empirical approaches cf chart, and the 818 chart which lead to wg actually result in a maximum aggregate packing density. Grading requirements of fine aggregates astm c33 bulking of sand. Section 800 coarse aggregate georgia department of. Our testing equipment also includes abrasion testing, rock testing, moisture and specific gravity testing equipment.
Concrete aggregate combined gradation example montana. Please include a link to any spreadsheets software for your optimized gradation spreadsheet software that are available online. Testing includes aggregate gradation and percent fractured crush count. Review available literature related to asphalt film thickness and asphalt mixture.
The sieve analysis database system for the quality control of construction aggregates and asphalt paving materials. Following tables provides details for grading limits of aggregates. Below is a chart showing the gradation range of both types of hot mix we provide. Gradation or distribution of different sized stones from penndot publication 408, section 703. Gradation measurement of asphalt mixture by xray ct images. The particle size distribution, or gradation, of an aggregate is one of the most influential aggregate characteristics in determining how it will perform as a pavement material. Minnesota department of transportation road and travel information, construction projects, regional offices, bid letting, future highway plans, hot topics, jobs, library, map sales, news. Chapter 2 sieve analysis and fineness modulus sampling since the reason for sampling aggregates is to determine the gradation particle size of the aggregate, it is necessary that they be sampled correctly.
Optimization of aggregate gradation combinations to. Gradlab gds gradation database system for aggregate quality control, asphalt quality control and soil grading records sieve analysis software by hugh lerwill computer software. Illinois aggregates cannot normally be combined to stay within the 8 18 rule, but they can be blended to lower the peak typically present on the 12 in. Appendix d indot course aggregate size specifications riprap gradation requirements percent smaller size, in. Microsoft powerpoint 02 aggregate gradation and sampling author.
Often, aggregates from more than one source or stockpile are used to obtain the final aggregate gradation used in a mix design. Aggregate materials are generally broken up into two classifications of size. Gradation is defined as the usage of each aggregate components in asphalt mixture, and it determines the aggregate skeleton structure, especially for coarse aggregate, which contributes the loadcarrying capability of the skeleton significantly. Obtain the aggregate gradation by crushing, screening, and blending processes as necessary. It is not garaunteed to be accurate for your specific needs, nor does take any responsibility for the.
In hma, gradation helps determine almost every important property including stiffness, stability, durability, permeability, workability, fatigue resistance, frictional resistance and moisture susceptibility roberts et. Provide openhearth oh, basic oxygen furnace bof, and electric arc furnace eaf steel slag aggregate known as. Aggregate gradation is the particle size distribution of both the stone and sand. Do you allow any manufactured materials as a substitution for aggregate. Perform blending calculations to achieve the mix design aggregate gradation. The vgstudio software is utilized for the reconstruction of the. If it didnt meet both requirements, we defined a combined aggregate as not wellgraded nwg. Illinois aggregates cannot normally be combined to stay within the 8 18. Department of transportation supplement 1069 prequalified aggregate supplier program february 8, 2002. Tricon materials standards information on coarse aggregate gradations sieve size percent passing, and fine aggregate gradations sieve size percent passing. The charts below show typical gradations of various products based on required specifications from agencies and organizations such as state dots, aashto, etc.
All white cells are input cells start by typing your name if printing is desired. Optimized aggregate gradation for hydraulic cement concrete. For certain mixtures, it is beneficial to include an intermediate aggregate, in addition to the traditional rock and sand, to improve aggregate packing. Do you have a spreadsheet or software that you use for optimized aggregate gradation mixes, and do you have one you require contractor to use. Included is the production of three optimization charts that may be required to be included in the concrete mix. The cf and 8 18 charts for the wg and nwg combined aggregates are plotted in fig. Effect of continuous wellgraded combined aggregate grading on concrete performance phase a. Concrete aggregate combined gradation example page 6 of 6 it is generally desirable to. Development and implementation of aggregate grading for pavements. Concrete aggregate combined gradation example general mdt is moving toward optimized gradations for concrete aggregate. In hma, gradation helps determine almost every important property including stiffness, stability, durability, permeability, workability, fatigue resistance, frictional. Bank run crushed stone processed gravel fine aggregates.
Find your aggregate gradation find out the volume and consistency of the. The source may also use mixture aggregate technicians for sampling and gradation testing only. Value, mnpave, aggregate gradation, shape, aggregates by shape and surface texture. Aggregate gradation optimization literature search. Trial blends of these different gradations are usually calculated until an acceptable final mix design gradation is achieved. Now, the focus has been to advance the knowledge of. Table 2 gives the washed gradation of the aggregate used in the asphalt paving mixture. Introduction this document provides technical design guidance for aggregate surfacing on existing soils subgrade and applies to the conservation practices cp listed below. The 8 18 rule is one method to characterize an aggregate blend. All aggregate shall be the specified type, class, and grade, and shall meet. Coarseness workability consolidation a new approach daniel cook, ashkanghaeezadeh, tyler ley, p. Strengththe influence of aggregate gradation on the compressive strength of finished. The presence of free moisture content in fine aggregate particles results in bulking.
Best value granular material for road foundations january 2012 6. The objective of wellgraded aggregate gradations is to proportion the aggregate volumes such that paste volume is reduced to a minimum. A guide to determining the optimal gradation of concrete aggregates. Gradation technician shall be under the direct supervision of the aggregate technician when testing gradation samples. Costs associated with the intermediate aggregate may be offset by reducing cement content and increasing the concrete quality. Aggregate, gradation, concrete, optimization, sand, coarseness factor. An asphalt cement shrp mrl designation aam1 was used in this study.
Use the 8 18 percentretained and the coarseness factor charts below to proportion combined aggregates. Use microsoft excel version 2000 or newer for forms in excel. We also have sieve shakers and material sample splitters for most. Since the combined aggregate grading as measured by the cf and 818 charts. Founded in 1904 and headquartered in farmington hills, michigan, usa, the american concrete institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensusbased standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design. S 20 cmm 860 materials testing and acceptance aggregates. Effect of continuous wellgraded combined aggregate.
A side issue related to the general concept of optimization is the socalled 818. Development and implementation of aggregate grading for pavements daniel cook, ashkan ghaeezadeh, nick seader, bruce russell. Aggregate is a collective term for sand, gravel and crushed stone mineral materials in their natural or processed state nssga 1991. Department of transportation supplement 1069 prequalified aggregate supplier program february 8, 2002 1069. The goal is to develop the components of a new granular material best value software module to be added.