UPAYA MENINGKATKAN KUAT GESER TANAH LEMPUNG DENGAN MEMANFAATKAN LIMBAH PLASTIK

Abstract

ABSTRACT
The objectives of this study was to determine: (1) the effect of the addition of plastic waste ofmineral water
containers (in some variations and percentages) to qu (the value of unconfined compressive strength) of clay, (2)
the effect of the addition of the plastic waste to φ (the shear strength) of clay, (3) the effect of the addition of the
plastic waste to c (the adhesiveness) of clay. This study applied anexperiment method. The plastics were cut into
the sizes of 1x1 cm and 1x0,5 cm, then they were mixed in the clay, compacted, and then tested. Theclay
samples were taken from Wates (Jl. Wates km 7) Kulonprogro and Kasongan Bantul at a depth of -0.20 m. The
plastic waste used was the mineral water container (PET plastic). The results showed that the addition of plastic
waste ofmineral water containers: (1) raises the value of qu (unconfined compressive strength) of the clay from
Wates with 1% - 2% of plastics and the clay from Kasongan with 1% of plastics (2) raisesthe shear strength φ, if
the level of plastics was 1% - 3% in the clay from Wates and Kasongan but if only the plastics were cut into small
pieces (c) decreases the adhesion, unless the plastic were in small sizes at the level of 3% (clay from Wates) and
if the plastics were in large size (clay from Kasongan).
Keywords: clay, plastic waste, unconfined compressive strength
ABSTRAK
Penelitian ini bertujuan untuk: (1) mengetahui pengaruh penambahan potongan limbah plastik wadah air mineral
(pada beberapa variasi dan persentase) terhadap qu (nilai kuat-tekan-bebas) tanah lempung, (2) mengetahui
pengaruh penambahan potongan limbah plastik terhadap φ (sudut kuat geser) tanah lempung, (3) mengetahui
pengaruh penambahan potongan limbah plastik terhadap c (lekatan) tanah lempung.Penelitian ini menggunakan
metode Eksperimen. Limbah plastik dipotongukuran 1x1 (cm) dan 1x 0,5 (cm) kemudian dicampurkan pada tanah
lempung, dipadatkan, lalu diuji kuat tekan bebasnya. Sampel lempung diambil dari Wates (Jl. Wates km 7)
Kulonprogo dan Kasongan Bantul pada elevasi -0,20 m. Limbah Plastik menggunakan bekas wadah air mineral
(plastik jenis PET).Hasil penelitian menunjukkan bahwa penambahan potongan limbah plastik ukuran tersebut
pada lempung dapat: (1) menaikkan nilai qu (kuat tekan bebas) tanah pada kadar plastik 1%-2% lempung Wates
dan kadar plastik 1% pada lempung Kasongan(2) menaikkan sudut-kuat-geser φ jika kadar plastik 1%-3%
lempung Wates dan Lempung Kasongan tetapi hanya jika plastiknya dipotong kecil (c) menurunkan lekatan,
kecuali jika potongan plastik ukurannya kecil pada kadar plastik 3% (lempung Wates) dan jika potongan plastik
ukurannya besar (lempung Kasongan).
Kata kunci: lempung, limbah plastik, tekan bebas