1271:
127:
recrystallization, much favoring the formation of metakaolin and the use of thermally activated kaolin clays as pozzolans. Also, because the octahedral layer is directly exposed to the interlayer (in comparison to for instance T-O-T clay minerals such as smectites), structural disorder is attained more easily upon heating.
57::Metakaolin is a dehydrated form of kaolinite, a type of clay mineral. Kaolinite-rich minerals are also referred to as china clay or kaolin, which are traditionally utilized in the production of porcelain. The grain size of metakaolin is less than that of cement particles, but it's not as minuscule as silica fume.
105:
process due to the large amount of energy required to remove the chemically bonded hydroxyl ions. Above the temperature range of dehydroxylation, kaolinite transforms into metakaolin, a complex amorphous structure which retains some long-range order due to layer stacking. Much of the aluminum of the
96:
does not contain interlayer cations or interlayer water. The temperature of dehydroxylation depends on the structural layer stacking order. Disordered kaolinite dehydroxylates between 530 and 570 °C, ordered kaolinite between 570 and 630 °C. Dehydroxylated disordered kaolinite shows higher
126:
and a defect Al-Si spinel. Reported optimum activation temperatures vary between 550 and 850 °C for varying durations, however the range 650-750 °C is most commonly quoted. In comparison with other clay minerals kaolinite shows a broad temperature interval between dehydroxylation and
230:, which occurs when calcium is transported by water to the surface where it combines with carbon dioxide from the atmosphere to make calcium carbonate, which precipitates on the surface as a white residue.
146:
at ordinary temperature and in the presence of moisture to form a strong slow-hardening cement. It is formed by calcining purified kaolinite, generally between 650 and 700 °C in an externally fired
53:
The quality and reactivity of metakaolin is strongly dependent of the characteristics of the raw material used. Metakaolin can be produced from a variety of primary and secondary sources containing
416:
Fernandez, R.; Martirena F.; Scrivener K.L. (2011). "The origin of the pozzolanic activity of clay minerals: A comparison between kaolinite, illite and montmorillonite".
159:(ASR), particularly useful when using recycled crushed glass or glass fines as aggregate. The amount of slaked lime that can be bound by metakaolin is measured by the
110:(supplementary cementitious material) nearly complete dehydroxylation must be reached without overheating, i.e., thoroughly roasted but not burnt. This produces an
160:
1209:
362:
Kakali, G.; Perraki T.; Tsivilis S.; Badogiannis E. (2001). "Thermal treatment of kaolin: the effect of mineralogy on the pozzolanic activity".
1230:
577:
Gamelas, J.; Ferraz, E.; Rocha, F. (2014). "An insight into the surface properties of calcined kaolinitic clays: the grinding effect".
947:
657:
534:
Ferraz
Eduardo; AndrejkoviÄŤová Slávka; Hajjaji Walid; Velosa Ana LuĂsa; Silva AntĂłnio Santos; Rocha Fernando; et al. (2015).
1098:
772:
1189:
389:
Bellotto, M.; Gualtieri A.; Artioli A.; Clark S.M. (1995). "Kinetic study of the kaolinite-mullite reaction sequence".
299:
957:
687:
33:. Rocks that are rich in kaolinite are known as china clay or kaolin, traditionally used in the manufacture of
1163:
730:
650:
536:"Pozzolanic activity of metakaolins by the French standard of the modified Chapelle test: A direct methology"
203:
mix that exhibits favorable engineering properties, including: the filler effect, the acceleration of OPC
1204:
1179:
1093:
1060:
211:. The filler effect is immediate, while the effect of pozzolanic reaction occurs between 3 and 14 days.
1305:
1158:
972:
682:
603:
521:
176:
155:(OPC), and its major impact is seen within 24 hours. It also reduces the deterioration of concrete by
1194:
1136:
1055:
995:
810:
725:
252:
Improved color by lightening the color of concrete making it possible to tint lighter integral color.
643:
967:
712:
533:
1065:
942:
866:
757:
752:
240:
156:
1148:
891:
496:
151:. It is also reported that HRM is responsible for acceleration in the hydration of ordinary
106:
octahedral layer becomes tetrahedrally and pentahedrally coordinated. In order to produce a
1184:
1085:
1080:
1040:
952:
815:
443:
8:
1131:
1050:
820:
762:
208:
98:
1045:
962:
375:
1295:
1274:
1030:
1025:
1000:
982:
896:
876:
697:
204:
1153:
469:
Snellings, R.; Mertens G.; Elsen J. (2012). "Supplementary cementitious materials".
429:
1126:
1035:
901:
861:
740:
702:
615:
590:
586:
557:
547:
478:
425:
398:
371:
1300:
1070:
921:
825:
735:
314:
196:
152:
139:
111:
74:
1143:
1075:
916:
835:
805:
800:
692:
792:
192:
1289:
1116:
1015:
1005:
911:
324:
277:
Countertops, art sculptures (see for example the free-standing sculptures of
227:
1020:
906:
881:
674:
552:
535:
278:
830:
562:
482:
1121:
840:
777:
361:
342:
148:
143:
102:
42:
26:
388:
1225:
1010:
990:
402:
172:
119:
16:
Concrete admixture: calcined kaolinite exhibiting pozzolanic reactivity
1256:
309:
115:
93:
80:
68:
54:
34:
30:
23:
1240:
1235:
871:
666:
415:
319:
294:
249:
Reduced shrinkage, due to "particle packing" making concrete denser
200:
188:
107:
1199:
767:
304:
123:
579:
Colloids and
Surfaces A: Physicochemical and Engineering Aspects
101:
than ordered. The dehydroxylation of kaolin to metakaolin is an
926:
886:
720:
62:
38:
175:
surface properties of the metakaolins can be characterized by
845:
747:
255:
Higher thermal resistance due to increased temperature levels
635:
468:
576:
265:
High performance, high strength, and lightweight concrete
114:, highly pozzolanic state, whereas overheating can cause
223:
Reduced permeability (including chloride permeability)
187:
Considered to have twice the reactivity of most other
515:
142:
pozzolan, a finely-divided material that reacts with
199:with 8–20 wt.% (% by weight) metakaolin produces a
37:. The particle size of metakaolin is smaller than
1287:
1210:International Federation for Structural Concrete
246:Enhanced workability and finishing of concrete
651:
597:
130:
220:Increased compressive and flexural strengths
195:for concrete/cement applications. Replacing
658:
644:
71:deposits or tropical soils of lower purity
561:
551:
616:"Metakaolin | R-E-D Industrial Products"
166:
233:Increased resistance to chemical attack
1288:
471:Reviews in Mineralogy and Geochemistry
639:
182:
138:(HRM) is a highly processed reactive
87:
773:Ground granulated blast-furnace slag
271:Fibercement and ferrocement products
118:, to form a dead burnt, nonreactive
48:
1190:Institution of Structural Engineers
13:
497:"High Reactivity Metakaolin (HRM)"
444:"High Reactivity Metakaolin (HRM)"
83:tailings (if containing kaolinite)
14:
1317:
540:Acta Geodynamica et Geomaterialia
448:Advanced Cement Technologies, LLC
391:Physics and Chemistry of Minerals
300:Engineered cementitious composite
1270:
1269:
268:Precast and poured-mold concrete
608:
430:10.1016/j.cemconres.2010.09.013
274:Glass fiber reinforced concrete
688:Roman architectural revolution
591:10.1016/j.colsurfa.2014.04.038
570:
527:
489:
462:
436:
409:
382:
355:
41:particles, but not as fine as
1:
376:10.1016/s0169-1317(01)00040-0
348:
214:
665:
604:Filler effect of metakaolin.
501:Alkali-Silica Reaction (ASR)
418:Cement and Concrete Research
7:
1205:Portland Cement Association
1180:American Concrete Institute
288:
191:, metakaolin is a valuable
10:
1322:
683:Ancient Roman architecture
177:inverse gas chromatography
136:High-reactivity metakaolin
131:High-reactivity metakaolin
1265:
1249:
1218:
1195:Indian Concrete Institute
1172:
1109:
981:
935:
854:
791:
711:
673:
77:(if containing kaolinite)
29:form of the clay mineral
241:alkali-silica reactivity
259:
973:Alkali–silica reaction
731:Energetically modified
553:10.13168/AGG.2015.0026
522:modified Chapelle test
226:Reduced potential for
161:modified Chapelle test
157:Alkali Silica Reaction
483:10.2138/rmg.2012.74.6
167:Adsorption properties
92:The T-O clay mineral
958:Environmental impact
816:Reversing drum mixer
364:Applied Clay Science
236:Increased durability
327:(also very rich in
239:Reduced effects of
209:pozzolanic reaction
99:pozzolanic activity
1061:Self-consolidating
753:Water–cement ratio
403:10.1007/bf00202254
183:Concrete admixture
88:Forming metakaolin
75:Paper sludge waste
1306:Silicate minerals
1283:
1282:
1275:Category:Concrete
1056:Roller-compacting
877:Climbing formwork
726:Calcium aluminate
698:Roman engineering
284:Mortar and stucco
49:Kaolinite sources
1313:
1273:
1272:
1185:Concrete Society
996:Fiber-reinforced
811:Volumetric mixer
703:Roman technology
660:
653:
646:
637:
636:
630:
629:
627:
626:
620:R-E-D Industrial
612:
606:
601:
595:
594:
574:
568:
567:
565:
555:
531:
525:
519:
513:
512:
510:
508:
493:
487:
486:
466:
460:
459:
457:
455:
440:
434:
433:
413:
407:
406:
386:
380:
379:
359:
338:
337:
336:
1321:
1320:
1316:
1315:
1314:
1312:
1311:
1310:
1286:
1285:
1284:
1279:
1261:
1245:
1214:
1168:
1105:
977:
931:
850:
826:Flow table test
787:
707:
669:
664:
634:
633:
624:
622:
614:
613:
609:
602:
598:
575:
571:
532:
528:
520:
516:
506:
504:
495:
494:
490:
467:
463:
453:
451:
442:
441:
437:
414:
410:
387:
383:
360:
356:
351:
335:
332:
331:
330:
328:
315:Portland cement
291:
262:
217:
197:portland cement
185:
169:
153:portland cement
140:aluminosilicate
133:
90:
51:
17:
12:
11:
5:
1319:
1309:
1308:
1303:
1298:
1281:
1280:
1278:
1277:
1266:
1263:
1262:
1260:
1259:
1253:
1251:
1247:
1246:
1244:
1243:
1238:
1233:
1228:
1222:
1220:
1216:
1215:
1213:
1212:
1207:
1202:
1197:
1192:
1187:
1182:
1176:
1174:
1170:
1169:
1167:
1166:
1161:
1156:
1151:
1146:
1144:Concrete block
1141:
1140:
1139:
1134:
1132:voided biaxial
1129:
1124:
1113:
1111:
1107:
1106:
1104:
1103:
1102:
1101:
1096:
1088:
1083:
1078:
1073:
1068:
1063:
1058:
1053:
1048:
1043:
1038:
1033:
1028:
1023:
1018:
1013:
1008:
1003:
998:
993:
987:
985:
979:
978:
976:
975:
970:
965:
960:
955:
950:
945:
939:
937:
933:
932:
930:
929:
924:
919:
914:
909:
904:
899:
894:
889:
884:
879:
874:
869:
864:
858:
856:
852:
851:
849:
848:
843:
838:
836:Concrete cover
833:
828:
823:
818:
813:
808:
806:Concrete mixer
803:
797:
795:
789:
788:
786:
785:
780:
775:
770:
765:
760:
755:
750:
745:
744:
743:
738:
733:
728:
717:
715:
709:
708:
706:
705:
700:
695:
693:Roman concrete
690:
685:
679:
677:
671:
670:
663:
662:
655:
648:
640:
632:
631:
607:
596:
569:
563:10400.26/38418
546:(3): 289–298.
526:
514:
488:
461:
435:
408:
381:
370:(1–2): 73–80.
353:
352:
350:
347:
346:
345:
340:
333:
322:
317:
312:
307:
302:
297:
290:
287:
286:
285:
282:
275:
272:
269:
266:
261:
258:
257:
256:
253:
250:
247:
244:
237:
234:
231:
224:
221:
216:
213:
184:
181:
168:
165:
132:
129:
89:
86:
85:
84:
78:
72:
66:
50:
47:
15:
9:
6:
4:
3:
2:
1318:
1307:
1304:
1302:
1299:
1297:
1294:
1293:
1291:
1276:
1268:
1267:
1264:
1258:
1255:
1254:
1252:
1248:
1242:
1239:
1237:
1234:
1232:
1229:
1227:
1224:
1223:
1221:
1217:
1211:
1208:
1206:
1203:
1201:
1198:
1196:
1193:
1191:
1188:
1186:
1183:
1181:
1178:
1177:
1175:
1173:Organizations
1171:
1165:
1162:
1160:
1157:
1155:
1152:
1150:
1147:
1145:
1142:
1138:
1137:slab on grade
1135:
1133:
1130:
1128:
1125:
1123:
1120:
1119:
1118:
1115:
1114:
1112:
1108:
1100:
1097:
1095:
1092:
1091:
1089:
1087:
1084:
1082:
1079:
1077:
1074:
1072:
1069:
1067:
1066:Self-leveling
1064:
1062:
1059:
1057:
1054:
1052:
1049:
1047:
1044:
1042:
1039:
1037:
1034:
1032:
1029:
1027:
1024:
1022:
1019:
1017:
1014:
1012:
1009:
1007:
1004:
1002:
999:
997:
994:
992:
989:
988:
986:
984:
980:
974:
971:
969:
966:
964:
961:
959:
956:
954:
951:
949:
946:
944:
941:
940:
938:
934:
928:
925:
923:
920:
918:
915:
913:
910:
908:
905:
903:
900:
898:
895:
893:
890:
888:
885:
883:
880:
878:
875:
873:
870:
868:
867:Cast-in-place
865:
863:
860:
859:
857:
853:
847:
844:
842:
839:
837:
834:
832:
829:
827:
824:
822:
819:
817:
814:
812:
809:
807:
804:
802:
799:
798:
796:
794:
790:
784:
781:
779:
776:
774:
771:
769:
766:
764:
763:Reinforcement
761:
759:
756:
754:
751:
749:
746:
742:
739:
737:
734:
732:
729:
727:
724:
723:
722:
719:
718:
716:
714:
710:
704:
701:
699:
696:
694:
691:
689:
686:
684:
681:
680:
678:
676:
672:
668:
661:
656:
654:
649:
647:
642:
641:
638:
621:
617:
611:
605:
600:
592:
588:
584:
580:
573:
564:
559:
554:
549:
545:
541:
537:
530:
523:
518:
502:
498:
492:
484:
480:
476:
472:
465:
449:
445:
439:
431:
427:
423:
419:
412:
404:
400:
396:
392:
385:
377:
373:
369:
365:
358:
354:
344:
341:
326:
325:Rice husk ash
323:
321:
318:
316:
313:
311:
308:
306:
303:
301:
298:
296:
293:
292:
283:
280:
276:
273:
270:
267:
264:
263:
254:
251:
248:
245:
242:
238:
235:
232:
229:
228:efflorescence
225:
222:
219:
218:
212:
210:
206:
202:
198:
194:
190:
180:
178:
174:
164:
162:
158:
154:
150:
145:
141:
137:
128:
125:
122:, containing
121:
117:
113:
109:
104:
100:
95:
82:
79:
76:
73:
70:
67:
64:
60:
59:
58:
56:
46:
44:
40:
36:
32:
28:
25:
21:
1149:Step barrier
1110:Applications
1021:Nanoconcrete
907:Power trowel
892:Power screed
882:Slip forming
855:Construction
782:
623:. Retrieved
619:
610:
599:
582:
578:
572:
543:
539:
529:
517:
505:. Retrieved
503:. Metakaolin
500:
491:
474:
470:
464:
452:. Retrieved
450:. Metakaolin
447:
438:
421:
417:
411:
394:
390:
384:
367:
363:
357:
279:Albert Vrana
186:
170:
135:
134:
91:
61:High purity
52:
19:
18:
1127:hollow-core
1086:Waste light
1081:Translucent
1041:Prestressed
968:Segregation
953:Degradation
841:Cover meter
778:Silica fume
713:Composition
477:: 211–278.
424:: 113–122.
397:: 207–217.
343:Silica fume
149:rotary kiln
144:slaked lime
103:endothermic
43:silica fume
1290:Categories
1226:Eurocode 2
1164:Structures
1051:Reinforced
1011:Lunarcrete
991:AstroCrete
948:Durability
943:Properties
821:Slump test
793:Production
783:Metakaolin
625:2024-02-20
349:References
215:Advantages
207:, and the
179:analysis.
173:adsorption
120:refractory
20:Metakaolin
1257:Hempcrete
1219:Standards
1046:Ready-mix
963:Recycling
758:Aggregate
741:Rosendale
585:: 49–57.
310:Kaolinite
205:hydration
193:admixture
189:pozzolans
116:sintering
112:amorphous
94:kaolinite
69:Kaolinite
55:kaolinite
35:porcelain
31:kaolinite
24:anhydrous
1296:Concrete
1250:See also
1241:EN 10080
1236:EN 206-1
1231:EN 197-1
1090:Aerated
1031:Polished
1026:Pervious
1001:Filigree
897:Finisher
872:Formwork
736:Portland
667:Concrete
320:Pozzolan
295:Concrete
289:See also
201:concrete
108:pozzolan
81:Oil sand
65:deposits
27:calcined
1200:Nanocem
1159:Columns
1036:Polymer
936:Science
902:Grinder
862:Precast
768:Fly ash
675:History
507:Oct 22,
305:Fly ash
124:mullite
22:is the
1301:Cement
1122:waffle
1071:Sulfur
927:Tremie
922:Sealer
887:Screed
831:Curing
721:Cement
454:May 7,
63:kaolin
39:cement
1154:Roads
1076:Tabby
983:Types
917:Float
846:Rebar
801:Plant
748:Water
243:(ASR)
1117:Slab
1099:RAAC
1016:Mass
1006:Foam
912:Pump
509:2010
456:2010
260:Uses
171:The
1094:AAC
587:doi
583:455
558:hdl
548:doi
479:doi
426:doi
399:doi
372:doi
329:SiO
1292::
618:.
581:.
556:.
544:12
542:.
538:.
499:.
475:74
473:.
446:.
422:41
420:.
395:22
393:.
368:20
366:.
163:.
45:.
659:e
652:t
645:v
628:.
593:.
589::
566:.
560::
550::
524:,
511:.
485:.
481::
458:.
432:.
428::
405:.
401::
378:.
374::
339:)
334:2
281:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.