《道路与桥梁建筑材料》课程教学课件（PPT讲稿）Soils, unbound granular materials and cement stabilized materials

Soils, unbound granularmaterials and cement stabilizedmaterialsprof. dr. ir. Andre A.A. MolenaarTUDelftDelftUniversityofTechnology

Vermelding onderdeel organisatie August 31, 2025 1 Soils, unbound granular materials and cement stabilized materials prof. dr. ir. André A.A. Molenaar

Poor soil conditions stop trafficTUDelft

2 Poor soil conditions stop traffic

TUDelft

3

Traffic-ability of soils is a hot item in the militaryWhenis movement of equipment not possibleAugust31,2025TUDelft

August 31, 2025 4 Traffic-ability of soils is a hot item in the military When is movement of equipment not possible

This unevenness is due to settlement of weaksubsoil but this also happens when youhaveswelling soils!August31,2025TUDelft

August 31, 2025 5 This unevenness is due to settlement of weak subsoil but this also happens when you have swelling soils!

Three physical states of soilaggregate mixtures喜High stability whenHigh stability whenHighstabilitywhenconfinedconfinedconfinedANDdryNocohesionHighcohesionwhenHighcohesionwhendrydry,low when wetHighangleofinternalHighangle of internalNo angle of internalfrictionfrictionfrictionwhen wetNotaffected byModeratelyaffectedbyGreatlyaffectedbymoistureconditionsmoistureconditionsmoistureconditionsVerydifficulttoNotdifficultto compactModeratelydificulttoat rightmoisturelevelcompactcompactAugust31,2025TUDelft

August 31, 2025 6 Three physical states of soil aggregate mixtures High stability when confined High stability when confined High stability when confined AND dry No cohesion High cohesion when dry High cohesion when dry, low when wet High angle of internal friction High angle of internal friction No angle of internal friction when wet Not affected by moisture conditions Moderately affected by moisture conditions Greatly affected by moisture conditions Very difficult to compact Moderately dificult to compact Not difficult to compact at right moisture level

Previous slideindicatedimportance ofgradation and characteristics of the finesAugust31,2025TUDelft

August 31, 2025 7 Previous slide indicated importance of gradation and characteristics of the fines

Particle sizedistributioncurvesforsandsandgravelsBRITISHSTANDARO_SIEVE SIZES636002126-32037-5L2015013004251-18103-3514075200800285OOOONISS1AOINEEFullercurveT200-0020-006mm0-020-060-20620602C200BOOmFineFineMediumCoarseMediumFineCosrseMediumCosreCLAYCOBBLESBOULDERSSILTSANDGRAVELTTUDelft

August 31, 2025 8 Particle size distribution curves for sands and gravels

FullercurveIf particle size distribution curve is according toFuller,thentheparticlesfit so nicetogetherthat one has the densest packing and sothehighest stability.Equation:Px=V(Dx/ Dmax)Px = percentage by mass having diametersmallerthanDxDmax=maximum particle sizeAugust31,2025ATUDelft

August 31, 2025 9 Fuller curve • If particle size distribution curve is according to Fuller, then the particles fit so nice together that one has the densest packing and so the highest stability. • Equation: px =  (Dx / Dmax) px = percentage by mass having diameter smaller than Dx Dmax = maximum particle size

Particle sizedistributioncurvesforsands,silts and claysBRITISHSIANOARDSIEVESIZES632126020200ODNISSBDVINO-008020-0020-020-06208o200eoorFuneMedrunFindCOBBLESBOULDERSSILTTTUDelft

August 31, 2025 10 Particle size distribution curves for sands, silts and clays