CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="120"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "publications.waset.org",cType: 'non-interactive',cRay: '913520661d078819',cH: 'kaG4DwFDogphRMxCpZO_RtM_hv4XcficycgNE2iFNfY-1739788483-1.2.1.1-X0lQfWAQ3KrUX020AHzunRGrjmtjy12Qu4fTRQ___hd8e.E2YZxNNWsHKJdZs.jz',cUPMDTk: "\/abstracts\/search?q=subgrade&__cf_chl_tk=TAaPuJi2DJdlkNKZiovmNbp4w_slQen.AU8zzQTvur0-1739788483-1.0.1.1-MYtOMuCsPsosRnIqkND4SZDkfdqmhijlkBv8zxFTQPA",cFPWv: 'b',cITimeS: '1739788483',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/abstracts\/search?q=subgrade&__cf_chl_f_tk=TAaPuJi2DJdlkNKZiovmNbp4w_slQen.AU8zzQTvur0-1739788483-1.0.1.1-MYtOMuCsPsosRnIqkND4SZDkfdqmhijlkBv8zxFTQPA",md: "tGvXymdt_EADHX2lt_x0pWXJrvdtd4ukYH8n2IM3vmE-1739788483-1.2.1.1-IEEka.tCqSYxJ4_J.5LqxVfK.bG4V9wggxtl3PzvRkmyC7vZLUjSGZKY_zlNZENuI53DPBl.w.Wucst0CTuWGbpeD89vJi65ZisDVhZ9JQsSSEpMp0Ir5Bkm0m6SG7ysmTaF_oxP81n3bWY4BPdOxB2vf3fcyUP4xjEQCpHx7MtlWWvcjdMlA3xl61n9VQDegJjDV03IhfPDzGCxtN16NPVw4lo1FxFU_OBmkH0523RnlQVbBppZIJSqDh1bw1sORHBflwToJw96vZ3nf9YR3np5jM8a3hczz1Ze6uZc_T_A7s02_3TiZD.4axqg6ZM9Lh4wCnNbs4GZR77K.qCTXtyxr_qYRtQjvwMgvmbT80tycHnDuPywUw6Bd4cSfty2Mxklgeee1QaRwDZ577FG8fORW9albzeyBAgNcmBtNvV5OFV_QrbCjjhnxe0b3kWEOCBBnxI6wy6kM4SzDiA8Z7TB4MuAsHfFuKEIX4yVBj7rTqfuTMx0_cG.WwuU1ZUCnIrbL9YbxFJySeXD_74dIIKd3C9AbM7H5h3xcsC22WdN9gepvUlclmdo3P1Tsy4jaI4AWxby_Jh7DwiiDQ6UNv4SwQo0WV9A6W4TPp7VNayBiGnU_NJM9YN4iiH4GKJ5lLyTUBjCnKUBDXT9dHeZc.KX3DNjP42S4eCMCTfBLumLTPXmnCvcTpZX_sHFwh7s1d0d0C57.EEicmK.o3z5TkzPsccIKNU9UEPRRrrI..rOoDytok1XPC7aBgZc1dbNrHOBtQXAN0F9je23xUdVVx7VbzWkx1aAJWMNA7rIxmkuNgVLwzcjkSEY0V2IZjwuyy5LwbdTLW6SldQBWmGaAvK4kA1AZdxRuBo9oQKFs81Bi96XB0KXIG0lMADoJMLvQIGNXUCdvCemLxj2XLL1TlOszNAvzZ2KJfDXueUdbkJPRDd7v30verSnAPwFEbbdVqIiB9n6QkjknCY6Jsuksc3iplgbVH6rx0LzE9Q8OOk166__JP6BHP873sWMcxxv2QstmRNeCweZwh2Gxc7msEVI4u3UhgBQc7AWsfM6U1YwEE21qAUv8YfQ._pyk1hONqAMBTzxX2dbOjYbqU6xJ_iwtrRLPtmh9Czmy9mtnjTqNMLxmyHruP1DpqEWVhrtIKWqq2WD22tflgmRR7dYOjozpqnYpla_szi3XmTW3ZGlRYCQu0FY8fs.81c3fSVoayowyEJPh2OYDsVEzMUE8zHDDzFCxs7Z9xDMjmZpNFgkXQIUuAgz4_02Migni14nJIyq9qFqLmroZ05amSElirZksfM9WMhHoGOJg92VPunNJk3OCYY0ef2VpnoCo15gBB269dQoc9FLQnYiTqHltASvIGzP78GAOpYfSoEQIsQKEQjzu6nhQ1HSRNv9CLKtpfL5W0MzC1pEMwB.NfE0tmTODgH2Kl2E3DxsjvX3_Xj2c05f7Tjqw8j2Kln8j3o2v3j9Rp2y7oaVq5tMG8w5n4FLuko9jw.OJWtPrDIQqmhiGrm6P0S1JypLcLC_CbdOXTkfiu90InI_OxrzTltn7WQQ0cYZgZRPE5abSFDjST50cljvg8Ztd1y2GxkxvI_7IVaoY6QEoZEk_TpsMbH.unOpRBcQYZzhLIfUcVwhbp8XiYNeLj1aYROG9udesZyFfUetYnNYhcJC7yDD.xF4i68hl3U9.fJweKGDgiut1nqzFH8bbucXJ9TsxlJCriJZcQj2tkSMcMDv6yD..M1vx2RRCfYPcB0ZHUYS0yRoDxksFHKBSrJO7bn4n_OnQBP74Tu3CLxtlPixau8FTli9r2ty5oKOQYPpb9whUs6GCUO8WzL_DuTwt8Krx7T91s83wm91igHBVo4dZNWdusBWIBlhWIOWvUJSrvOJ1D.gBX4bz0fb9wzRa_YGRjfQtnUFvw1lkqrNqzgniaPU8gNWSw",mdrd: "0Q1_E2u5M2bakTUqD1o89NsZRIuHrXwEdkhbrUn_fB0-1739788483-1.2.1.1-92cBi7YOFsIc8DfYsmaqEj_HGQIuFCshovD8kLyKXo968VH7LsuZ0dBZFhSrDSEmI.WGycoDP1CDoRw.D0YNyaSEMa1DVLGOIgotifm3QwivrF7CxfBvsDRP5UJbtHAdFBZkb1kEQXRbEyavFUFHrzUOMTSsKViUDXiyRXzTCl1mWHtPqE4ATnk4BQCIKcP.wxBl3Epr5AjFU7fo30W4JYyARHg3L9fI0JPIB1HCAqIKmTLlFhh_bmYu1j7x1dc5amoKwXyIZnqRUPxnyWl0w0Nw1iiLcanfH0prBXrCy9e6BxGz_iPBrJ.YpUVuWz9DqH_aYuorZXByX9mczBGkA_1TSnyZfkLwHU0qCiaYu3H5uX.T9MGVfGTjd6fCjXtGnSAt_xvfs1bxtkKm4PjztZRDQAAf96boX9FF3XyRWsSEnoFENDsmxXTAA.OTnGexmzmeM4KnYi7aY0yAPwjjwfE_ZX.7R3Uox0N7scHZG1xK2LZ7V3_g42CclUjQJfCbGxhZ._g2iXkbf9Q9cYxfcEvmLLo6NwtQ91wNtgvMtL0tLN78ZoixqNI73jxoPkB.ZJpNP_.H7NgfM_iA7oUw2QTWvw8Ho2zxL8yX1cuQ6p1ZsjXmktTt4tErPi8SzSKd26Qrw3NGwFXxyzC6kI_r0P4PSmSVzp3x7rU2K3.K3KF5kfMbVjqxx8R9qDfXv4YpNTQE3kZbrwrZV73vFo7CW78n6WJTahlzs.hLazdH.2jdhQ0BuSLE1PU7XKpOyGfMKdg8uQnRjmVbujpSKg.cy3QdpUHErVfcUlQxQm4LS1Cq0UHz38DF5tWL6oYPCPXRx.2ecraqyesy8m5LjjVeNIjpJZAh78d0L0VuZAhWwAG45J8KoYhpPr2u_5lCKCA6oxyraxERLjZ1bCnvwtyO2dOBOjtV.7ipz7i2PcVfkGeMWQLGS22cuMxj0ABKHXOpAfWihnYUA5CwdKQ6AjwU_wD4zq01CDJLIs53M.WyKsWWt38QqIcRxqW.k_s54DEImU9S4GphtreUTq9AuSfn_DSTeORz_QZnS34jJ1F_Wx006d0z6axOfgRCA6NgvMU3v8uszcZOYlWA6j_c7mwQQxwbFFbsEFBbAq9_5E91ypZ3WozPCR4l4B43zTNjpLq_VcLTk17JDTP2.9t_nqNpWT18mLslgUxPcCu76ym2KM7MJ6H8BUISZz9mpZEuOA1eBAMXz8k6a9iPAO8n.yT2t6phoDNVnVMxD0eOdKfB7GeJcZrwR3tYHsDFebpXyrAxWyb31utNfIkgtMFKywwTIasd82f.optq4PtF40HPH7ronvw6lX9l3tvyTyS8AehzZCpxIVXoCwZ4R9g7_pAIuHFDwghTyTTmtP6DyO7Y5rEmzzzfD3DGXBrSciZtW4P2pnxv64xG6.3WWdak3HNoGw11dYx.TvYu_JKLYbSGwVL65tm6_062y6VkX1hDQ7OLKtXhpeE1fzdiw5Nhj0Z_Jytw0YL8hcOOk4PLiBfhODqdWSJn.7rOvCMha0wNJgafzj6BYzGBp7qZCbVkg6yqKVTRLxLKOIGT8BQEypd4nO9lycyFpDot_heX.K8eGwY5Y1dGwxje6I7Rw8Ps42BO7n6BUCchPLtPVSZa8J0OLPpeYcr7XYN2fWAh4x3Ct.fOckAjkgD2QDHwkxPNEHHah8wUHc5jq0_EkJl6meG5Vb2BFkMDe9BBEfWddSwxZo4W8fQiujmqoBt772E0ZkUV9d3zHRRcINk8uY0UIUjr9iskHn2EYZqhShFusugXlgQDirasDJH.U3lqPuGdWi6HZCDRUAunWn4DIpEC0lJOWgo5876y4trM0aA1Wjeaw5dh1tShVG5.xQw7TZ3lw7j62snnLKGKBvzzsMWAJ0QwPXavgnEcX.EP3Iu.pGY7zknTYRP.51CV_0vBLUbRw_rnCLkasE8bSXGPoFbt9595CiXIhiVSCwAbS.UIUnfSkmK2"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=913520661d078819';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/abstracts\/search?q=subgrade&__cf_chl_rt_tk=TAaPuJi2DJdlkNKZiovmNbp4w_slQen.AU8zzQTvur0-1739788483-1.0.1.1-MYtOMuCsPsosRnIqkND4SZDkfdqmhijlkBv8zxFTQPA" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>