2012 2011 €m €m Raw materials   643   648  Work-in-progress (i)  91   88  Finished goods  1,663   1,550  Total inventories at the lower of cost and net realisable value  2,397   2,286  2012 2011 €m €m Current Trade receivables  1,755   1,879  Amounts receivable in respect of construction contracts (i)  406   417  Total trade receivables, gross  2,161   2,296  Provision for impairment (126) (153) Total trade receivables, net  2,035   2,143  Other receivables (ii)  387   357  Amounts receivable from associates  3   2  Prepayments and accrued income  167   161  Total  2,592   2,663  Non-current  Other receivables   86   62  At 1 January  153   151  Translation adjustment  -  1  Provided during year  41   56  Written-off during year (65) (50) Recovered during year (3) (5) At 31 December  126   153  Neither past due nor impaired  1,608   1,731  Past due but not impaired: - less than 60 days  225   232  - 60 days or greater but less than 120 days  117   107  - 120 days or greater  55   49  Past due and impaired (partial or full provision)  156   177  Total  2,161   2,296  CRH 97 Trade receivables and amounts receivable in respect of construction contracts are in general receivable within 90 days of the balance sheet date.  The aged analysis of gross trade receivables and amounts receivable in respect of construction contracts at the balance sheet date was as follows: Information in relation to the Group’s credit risk management is provided in note 22 to the financial statements. The movements in the provision for impairment of receivables during the financial year were as follows: The carrying amounts of current and non-current trade and other receivables approximate their fair value largely due to the short-term maturities and nature of  these instruments. An analysis of the Group’s cost of sales expense is provided in note 3 to the financial statements. Write-downs of inventories recognised as an expense within cost of sales amounted to €12 million (2011: €14 million). None of the above carrying amounts has been pledged as security for liabilities entered into by the Group. (i)  Work-in-progress includes €1 million (2011: €8 million) in respect of the cumulative costs incurred, net of amounts transferred to cost of sales under  percentage-of-completion accounting, for construction contracts in progress at the balance sheet date.  17. Inventories 18. Trade and Other Receivables Provision for impairment Aged analysis (i)  Includes unbilled revenue at the balance sheet date in respect of construction contracts amounting to €137 million (2011: €121 million). (ii)  Other receivables include retentions held by customers in respect of construction contracts at the balance sheet date amounting to €66 million (2011: €70 million).