Investigation of MSWI mechanical properties based on the amount of - PowerPoint PPT Presentation

Investigation of MSWI mechanical properties based on the amount of reactive compounds PhD Student: V. Ca pra i Pro f.Dr. H.J.H. Bro uwe rs M.V.A F lo re a K . Sc ho llb a c h

General overview I ntro duc tio n a nd mo tiva tio ns • Cha ra c te riza tio n o f b y-pro duc ts (Physic a lly a nd c he mic a lly) • Po zzo la nic a c tivity inve stig a tio n (T GA, pa ste ) • Re a c tivity due to disso lutio n o f c he mic a l spe c ie s (I so the rma l c a lo rime try) • Suita b ility fo r c e me nt re pla c e me nt (E N 450) • Co nc lusio n • 1/ 12 Ove rvie w

T re a tme nts fo r Use o f b y-pro duc ts o ptimiza tio n Physic a l pro pe rtie s o f b y-pro duc t • (po ro sity, surfa c e a re a e tc .) Pre se nc e o f c o nta mina nts • (he a vy me ta ls, me ta llic Al a nd c hlo ride s) Alka li a c tiva te d b y-pro duc ts Re a c tivity a na lysis F o rma tio n o f ne w c o mpo und (C-A-S-H o r N-A-S-H) • I mmo biliza tio n o f c o nta mina nts • 2/ 12 Mo tiva tio n

Divide d in 3 main fractions : Sma ll ( s )  ϕ < 0.125 mm Me dium ( m )  1 mm > ϕ > 0.125 mm a rg e ( l )  1 mm > ϕ > 4 mm L Chemical composition Particle size distribution S S-s BA-s 1,253 0,8 3,435 1,156 100 2,543 0,929 1,324 2,387 1,24 Q5 13,274 9,347 10,274 90 9,334 Q6 S ludg e 1,966 2,422 BA‐S 17,15 80 14,516 LBA‐S 70 Cumulative fines [%] Sludge 1,584 1,32 60 CEM I 52.5 R 39,907 7,421 8,553 42,329 50 1,035 1,547 40 LBA-s 30 BA BA 1,488 2,064 1,345 0,915 2,376 20 10,707 12,894 10 0 2,389 16,721 B o tto m A sh 0,1 1 10 100 1000 Particle size [Micron] 1,442 7,184 37,954 1,467 Chemical characterization L L BA BA Alkaline phases Admixtures CaCO 3 content Metal Al Pozzolanic phases content L o w o rg a nic % w.t. % w.t % w.t. % w.t. c o nte nt S-s 1.61 0.1 10.5 30.40 B o tto m A sh BA-s 2.88 0.13 14.0 24.80 LBA-s 2.27 0.14 12.1 27.40 Cha ra c te riza tio n o f the b y-pro duc ts 3/ 12

Visualization of by-products (SEM) BA-s S-s S S ludg e BA BA B o tto m A sh Physical properties Admixtures Bulk density Specific gravity Moisture content Langmuir surface area L L BA BA g / c m 3 g / c m 3 m 2 / g % w.t S-s 0.48 3.9 56 38.6 L o w o rg a nic BA-s 0.56 4.1 21 25.2 c o nte nt LBA-s 0.56 3.7 21 14.6 B o tto m A sh 4/ 12 Cha ra c te riza tio n o f the b y-pro duc ts

Methodology Fraction tested: S-s, BA-s, L BA-s, Ca lc ium hydro xide (CH) Samples preparation: 50% e a c h fra c tio n + 50% CH + H 2 O (w/ b = 0.8) Reference: 50% SiO 2 + 50% CH Curing: Mo ulde d fo r 6 da ys a nd the n c ure d a t 97% RH Equipment: T G a na lysis Testing time: 7, 14, 28 da ys Results 105 1,E +00 5,E -01 100 0,E +00 DTG [%/min] -5,E -01 Mass [%] 95 -1,E +00 -2,E +00 90 Ma ss/ % -2,E +00 Ma ss/ % -3,E +00 Ma ss/ % DT G/ BA-s 85 -3,E +00 DT G/ BA-s+CH_7d -4,E +00 1. I nc re a sing po zzo la nic a c tivity within 14 DT G/ BA-s+CH_14d 80 -4,E +00 da ys. S-s ha s the g re a te r po zzo la nic 30 130 230 330 430 530 630 Temperature [C] a c tivity. S-s+CH 100 2. At 28 da ys inc re me nta l fo rma tio n o f 87 Ba -s+CH 85 L Ba -s+CH CH is re g iste re d. 80 72 CH content [%] 65 62 54 60 3. Hig h pre se nc e o f c a lc ium spe c ie s, 48 mo re tha n po zzo la nic , le a ds to the 39 39 40 sa tura tio n o f the so lutio n re spe c t o f CH. 20 0 7 d 14 d 28 d 5/ 12 Po zzo la nic a c tivity– T GA a na lysis

Methodology Fraction tested: S-s, BA-s, L BA-s, Ca lc ium hydro xide (CH) Samples preparation: 50% e a c h BA type + 50% CH Solution used: Wa te r (w/ b =0.8) Equipment: Co mpre ssive stre ng th te st Curing Conditions: 20 ° C ( ± 5 ° C) a nd 97% RH Results 2,0 Compressive strength [MPa] S-s+CH stre ng th 1,8 BA-s+CH stre ng th 1,6 L BA-s+CH stre ng th 1,4 1,2 1,0 0,8 0,6 0,4 0,2 0,0 0 5 10 15 20 25 30 Time [d] he increasing porosity , due to the pa rtic le s sha pe a nd initia l ma c ro -po ro sity, re duc e s the 1. T me c ha nic a l stre ng th. 2. Expansion cracks a re visib le a lo ng the mo rta rs, due to CH c rysta lliza tio n. Pre se nc e o f metallic Al inc re a se s the ma c ro po ro sity a nd g e ne ra te s a dditio na l c ra c ks. 3. 6/ 12 Po zzo la nic a c tivity– Me c ha nic a l stre ng th

Methodology Fraction tested: S-s, BA-s, L BA-s, CE M I 42.5 N (PC), Q5 (q ua rtz), Q6 Samples preparation: 75% PC+ 25% re pla c e me nt + H 2 O (w/ b = 0.5) Equipment: I so the rma l c a lo rime try Testing time: 5.5 da ys Results F ine r PSD fa vo urs the re a c tio n o f PC Pre se nc e o f BA-s, L BA-s a nd S-s re sults in a n inc re a sing re a c tio n de g re e o f PC Pre se nc e o f b o tto m a sh de la ys a nd pro lo ng s the re a c tio n o f C 3 S a nd Afm Re a c tivity in c o nc re te – K ine tic a na lysis 7/ 12

Methodology Fraction tested: S-s, BA-s, L BA-s, CE M I 42.5 N (PC), Q5 (q ua rtz), Q6 Samples preparation: 75% PC+ 25% re pla c e me nt + H 2 O (w/ b = 0.5) Equipment: I so the rma l c a lo rime try Testing time: 5.5 da ys Results Nomenclature Q: q ua rtz n: PSD o f the po wde rs OPC: CE M I 42.5 N Formulas PS D c o ntributio n = Cum. he at OPCQn – Cum. he at OPC Re ac tivity c o ntributio n= Cum. he at OPCBAn – Cum. he at OPCQn 35 Reaction contribution [%] Che mic a l c o ntrib utio n 30 PSD c o ntrib utio n 2,93 25 L BA-s pro vide s the hig he st c o ntrib utio n 2,93 12,85 20 in te rms o f re a c tivity a mo ng the po wde rs. 15 26,32 22,49 10 14,49 5 0 BA-s S-s L BA-s Bottom ash type Re a c tivity in c o nc re te – K ine tic a na lysis 8/ 12

Methodology Fraction tested: S-s, BA-s, L BA-s, CE M I 42.5 N (PC) Samples preparation: 75% PC+ 25% re pla c e me nt + H 2 O (w/ b = 0.5) Curing: 97 % RH Equipment: Stre ng th a c tivity inde x Testing time: 7, 14 da ys (28 da ys in pro g re ss) Results 1,2 1,09 1,08 S-sPC BA-sPC 1 0,89 L BA-sPC 0,85 0,85 0,79 0,77 0,76 0,8 Activity index [-] 0,66 0,6 0,4 0,2 0 L BA ha s the hig he r stre ng th 7 14 28 Time [days] de ve lo pme nt with S-s �������� �������� ����� ����� � ����������� �������� �� ������� S-s ha s fine r PSD a nd L BA-s ha s a lo we r ����������� �������� ��������� to ta l surfa c e a re a f SAI ≥ 0.75 the re pla c e me nt ma te ria l can be used in I Re a c tivity o f the pre c urso rs a ffe c ts the b uilding ma te ria ls f SAI < 0.75 the re pla c e me nt ma te ria l cannot be used in re a c tio n pro duc ts pe rfo rma nc e s I b uilding ma te ria ls 9/ 12 Re a c tivity in c o nc re te - Ca lc ula tio n o f SAI (stre ng th a c tivity inde x)

Conclusion Bo tto m a sh fro m He ro s Sluiskill B.V. (NL ) pre se nts simila ritie s with c la ss C fly a sh. • T he a c hie ve me nt o f sa tura tio n with re spe c t to CH inhibits the g e l fo rma tio n, a nd c o nse q ue ntly the stre ng th • de ve lo pme nt due to e xpa nsio n. Stre ng th a c tivity inde x re a c he s 1.08 within 14 da ys, displa ying a n impro ve me nt in the re a c tio n de g re e due to • the c he mic a l c o mpo sitio n o f b o tto m a sh. Afte r 28 da ys, the inde x de c re a se s a g a in, due to the re duc tio n o f po zzo la nic a c tivity o f the pa ste s a nd • e xpa nsio n phe no me na . Further research Me c ha nic a l tre a tme nts c a n b e a pplie d to inc re a se fine ne ss o f the po wde rs. • Alka li a c tiva tio n b a se d o n silic a te a nd/ o r a lumina te c a n b e a tte mpte d. • Alte rna tive silic a a nd a lumina so urc e b y-pro duc ts c a n pa rtia lly re pla c e the ma te ria l, suc h a s c la ss F fly a sh o r • hig h SiO 2 -Al 2 O 3 c o nte nt b o tto m a sh. De te rmina tio n o f T OC c a n he lp the unde rsta nding o f the re a c tio n pro c e ss. • 10/ 12 Co nc lusio ns

Que stio ns? 11/ 12

CaCO 3 content of by-products and Admixtures CaCO 3 content of pure ash CH at 28d % w.t. % w.t S-s 1.61 8.7 BA-s 2.88 19.75 LBA-s 2.27 8.8 25 S-s+CH 100 CaCO 3 content [% w.t] 87 19,75 Ba -s+CH 85 20 L Ba -s+CH 80 72 CH content [%] 65 62 15 54 60 48 39 39 8,8 8,7 10 40 5 20 0 0 7 d 14 d 28 d S-s BA-s L BA-s 13 Ca CO 3 fo rma tio n a t 28 da ys