Appendix: Aggregateproperties In this appendix some information on aggregate proper- Following limestones in the Table are gritstones (nine ties is given. First some properties of currently produced quarries), basalts (eight quarries) and granites (five quar- British aggregates, second some more generalized data ries). These rocks have higher polished stone values and on aggregate properties worldwide, and third some the gritstones, in particular with very high PSVs (all information on how weathering affects the properties above 60), are probably quarried predominantly for of aggregates. It is strongly emphasized that all the road surfacing aggregates as well as other purposes. information given in this Appendix must be regarded All the samples are of reasonably high strength (all as providing only a general appreciation of aggregate except two have 10% fines values of 150 kN or more) properties and should not be relied upon for specific illustrating the abundance of strong aggregates in test values for particular rocks or sources. Great Britain. For those few samples for which Los Angeles abrasion values have been reported, a good correlation with aggregate crushing value is seen (see Properties of some British aggregates Chapter 7). For the 21 samples for which magnesium sulphate Table A1 gives some test results for 96 aggregates soundness values have been reported, all save one from quarries in Great Britain. The information is have values of 90 or more, again indicating the ready not exhaustive but comes solely from fact-sheets availability of high-quality aggregates. In Table A1 issued by the suppliers or from information provided the magnesium sulphate soundness values quoted are to members of the Working Party by the suppliers. the percentages retained after the test, as specified in None of the data has been confirmed independently. the British Standard test specification (see Chapter 7). Where the quarry is not named in the Table this Although only four in number, the flint gravels omission is at the request of the supplier. Because show little variation in the properties reported. It aggregate properties are liable to vary, the test results is certain that flint gravels are under-represented in the Table should not be taken as an indication of in Table A1, because this aggregate is widely won in present production for particular quarries; instead southeast England. prospective users should seek up-to-date information The means and standard deviations given in Table from the suppliers. It should be borne in mind that A1 should only be used to obtain a general com- suppliers will not usually work poor quality sources parison of overall properties and their ranges for the of aggregate, nor provide data on them. different groups and should not be used for any The rock descriptions are those of the suppliers, other purpose. See also the caveat at the foot of the supplemented in some cases by reference to entries in Table regarding the data in general. directories of quarries (BGS 1984 and BACMI 1986). For further information on British aggregates, it can The classification in Table A1 is by the broad rock be noted that some properties of 78 British aggregates groups used in the aggregates industry, including currently used for bitumen macadam roadbase are many of the suppliers of the data. Tables AI.1 and given by Bullas & West (1991). The properties tabu- A1.2 describe crushed rock aggregates and Table lated are adherent silt and clay content, magnesium A1.3 gravel aggregates. sulphate soundness, aggregate impact value and 10% The Table reflects the fact that a common aggregate fines value, but neither the quarries nor their locations in England and Wales is limestone (see Chapter 4), are identified. this rock being supplied by 36 quarries. The domi- nance of limestone as an aggregate is undoubtedly because of the widespread outcrop of the Carboni- Properties of some aggregates from ferous Limestone in northern England, Derbyshire, worldwide sources Wales and the Mendips. Limestone is an aggregate suitable for many purposes except for the surfacing Table A2 gives some property data based primarily of roads, for which its polished stone value is often upon a synthesis of the test results for 285 samples too low (see Chapter 11), and railway track ballast of materials used as aggregate from sources around (see Chapter 12). the world including the United Kingdom. These test Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/4584785/9781862393790_backmatter.pdf by guest on 23 September 2021 300 "2, e,,'a q .o,.., ~'~ 'i ~ ~' '~ !~ ~ ~ ~ i ~ ~, '~ ~ ~ ~~ ~ o ~. i ~ ,-d < < [--, Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/4584785/9781862393790_backmatter.pdf by guest on 23 September 2021 301 ^ J "o ,.A " ~'~ o .~z ~ o "S ~ .- g o ~ ~,. ~ ~eeeeeee~ee,. .o o ~ o ~~i~i ~ ~ ~~~~~ ~ i ~.~~i 0 .E o ~ o . o o~ 0 ~'- ~ ;~ ~ zzzzz~ozz= ~z z z=z g~ ,, < !i ~ .~.~o ~ o~ Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/4584785/9781862393790_backmatter.pdf by guest on 23 September 2021 302 l l e~ ~ ~ oo ~o M ! ~ o ~ ~o ~ ~ oo ~ J~ c~ r~ ~~ Z Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/4584785/9781862393790_backmatter.pdf by guest on 23 September 2021 APPENDIX 303 TABLE A2. Comparison of some property data for various materials used as aggregate from worldwide sources including the UK. Each entry shows the range of values found and the median value in bold print (Sims & Brown 1998) Aggregate type* Water Unconfined Aggregate Aggregate 10% fines MgSO, (alphabetical absorption (%) compressive impact crushing value (kN) soundness* order) strength* (N/mm 2) value (%) value (%) (% loss) Andesite/Trachyte 1.4-7.9 210-280 12-31 11-12 170-190 0-96 (16) 3.0 -- 18 -- 180 4 Basalt 0.4-5.4 160-310 10-22 11-58 160-350 0-16 (18) 1.8 -- 18 19 220 2 Blasffurnace slag 2.0-4.8 90 15-33 33-42 55-210 (8) -- -- 28 34 85 -- Flint/Chert gravel 0.4-7.6 200 16-24 14-31 160-320 0-6 (96) 1.6 -- 20 16 2360 3 Gabbro/Dolerite 0.2-5.7 180-190 9-40 11-36 50-380 0-1 (10) 0.6 -- 18 19 190 Gneiss/Granulite 0.4--0.7 ~ 24-28 u 230 1-2 (5) 0.6 .... 1 Granite 0.2-1.9 150-250 11-35 13-32 75-280 1-31 (27) 0.6 ~ 21 24 155 2 Hornfels -- 340-370 16-17 1-15 m m (--) ......I Limestone/Dolomite 0.2-7.5 130-190 14-43 19-31 110-250 0-71 (58) 1.6 ~ 24 24 170 6 Quartzite gravel 0.7-1.2 280-390 13-22 16 140-250 (4) 0.7 -- -- -- 195 -- Sandstone 0.3-31.0 190-260 10-58 12-31 100-350 0-100 (20) 1.0 -- 18 15 200 4 Serpentinite gravel 0.5-6.6 -- 17-23 -- 150-260 3-17 (21) 1.4 -- 21 -- 240 8 Slate 1.8-3.0 -- 20-22 1 9-22 140-170 (2) ...... * Number of samples in the survey shown in parentheses for each aggregate type. Not all of the samples were tested for all of the properties shown. t Tests carried out on 25 mm diameter x 25 mm length cylinder specimens. After five cycles of the ASTM C88 test. results were obtained over a ten-year period in the recently published BS 812 method for soundness, London laboratories of Sandberg. Samples were except that the BS 812 method records the percentage included in the survey only when it was considered retained after 5 test cycles, where higher values would that the aggregate type has been established reliably, suggest better soundness. either because a petrographical examination had It is apparent that a wide range of values can be been carried out on the sample itself or occasionally expected for any property and any aggregate type, because the source was well known. Data were also so that the ranges given in Table A2 are presented taken into account from other published sources for indicative purposes only. Moreover, the nature (Phemister et al. 1946; Chapman 1967; Orchard of commercial materials assessment frequently 1976; Neville 1981). means that, in practice, only aggregate sources pre- Ranges of values are given for water absorption, established as likely to be suitable for use are sub- unconfined compressive (or crushing) strength, aggre- jected to laboratory testing. gate impact value (AIV), aggregate crushing value In Table A2, where the number of data is deemed (ACV), 10% fines value and magnesium sulphate sufficient, a median value is given (in bold print) in soundness. In all cases, except soundness, the testing addition to the range. Although the median values was carried out in accordance with the methods might be regarded as being sensibly 'typical' for given in BS 812 (see Chapter 7). each aggregate type, it is very important to recognize The soundness testing was carried out in accor- the magnitude of the potential deviations from that dance with the ASTM C88 method and the results value which are exemplified by the wide ranges represent percentage loss values after five test cycles, found in the survey. higher values thus suggesting poorer soundness. The The data in Table A2 show clearly that prospective soundness values given in Table A2 are broadly com- suitability cannot be judged on aggregate type alone. parable with the results likely to be obtained in the The median values are broadly acceptable for all Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/4584785/9781862393790_backmatter.pdf by guest on 23 September 2021 304 APPENDIX oo o~ .~o.~ d ~4 ~.~~ t--,. b.. ~..~~ b~ r r r e4 eq r gl ba ~ ~,~ o o ~4 < < Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/4584785/9781862393790_backmatter.pdf by guest on 23 September 2021 APPENDIX 305 TABLE A4.