cannot create pie chart [not able to bind value]

[sailendraw]

Hi, i am highchart plugin to display the pie chart but not able to generate pie, if i assign static value then pie chart is generated how ever when i pass php array it prints single line. here is my controller code.
$rawpercentage=$this->ConsumptionStock->query("select material_id,sum(quantity)*100/(select sum(quantity) from polychem.consumption_stock) as rawpercentage from polychem.consumption_stock group by material_id order by consumption_id;");
//Configure::write(‘debug’,0);
$this->set('rpercentage',$rawpercentage);
$rows = array();
foreach($rawpercentage as $raw):
$row[0] = $raw['consumption_stock']['material_id'];
$row[1] = $raw['0']['rawpercentage'];
array_push($rows,$row);
endforeach;
$dec=json_encode($rows, JSON_NUMERIC_CHECK);
$pieData[]=array();
array_push($pieData,$rows);
print_r($pieData);
//$pieData = $dec;
$chartName = 'Pie Chart';

            $pieChart = $this->Highcharts->create($chartName, 'pie');

            $this->Highcharts->setChartParams($chartName, array(
                'renderTo' => 'piewrapper', // div to display chart inside
                'chartWidth' => 600,
                'chartHeight' => 600,
                'chartMarginTop' => 60,
                'chartMarginLeft' => 90,
                'chartMarginRight' => 30,
                'chartMarginBottom' => 110,
                'chartSpacingRight' => 10,
                'chartSpacingBottom' => 15,
                'chartSpacingLeft' => 0,
                'chartAlignTicks' => FALSE,
                'chartBackgroundColorLinearGradient' => array(0, 0, 0, 300),
                'chartBackgroundColorStops' => array(array(0, 'rgb(217, 217, 217)'), array(1, 'rgb(255, 255, 255)')),
                'title' => 'Material Usage Statistics',
                'titleAlign' => 'left',
                'titleFloating' => TRUE,
                'titleStyleFont' => '18px Metrophobic, Arial, sans-serif',
                'titleStyleColor' => '#0099ff',
                'titleX' => 20,
                'titleY' => 20,
                'legendEnabled' => TRUE,
                'legendLayout' => 'horizontal',
                'legendAlign' => 'center',
                'legendVerticalAlign ' => 'bottom',
                'legendItemStyle' => array('color' => '#222'),
                'legendBackgroundColorLinearGradient' => array(0, 0, 0, 25),
                'legendBackgroundColorStops' => array(array(0, 'rgb(217, 217, 217)'), array(1, 'rgb(255, 255, 255)')),
                'tooltipEnabled' => TRUE,
                'tooltipBackgroundColorLinearGradient' => array(0, 0, 0, 50), // triggers js error
                'tooltipBackgroundColorStops' => array(array(0, 'rgb(217, 217, 217)'), array(1, 'rgb(255, 255, 255)')),
                'exportingEnabled' => FALSE
                    )
            );

            $series = $this->Highcharts->addChartSeries();

            $series->addName('Material Consumption')
                    ->addData($pieData);

            $pieChart->addSeries($series);

            $this->set(compact('chartName'));

please help me with this, i am new to both higchart and cakephp so any help would be really great favor to me.